World War II, which spanned from 1939 to 1945, was not the longest lasting war in our history but it was the deadliest. Between fifty to eighty million military and civilian died people in just six years. While World War II brought about massive fatality it also ended the Great Depression, the greatest economic crisis in history and spurred on an economic boom unlike any seen before. By 1945, 98% of the population had jobs that paid more than double what they had been paid before. (End of the Great Depression)
On the global trade stage, a series of laws helped maintain the neutrality of the US by restricting their trade with countries engaged in war. The Neutrality Acts prohibited trade with any foreign country at war except on a “cash-and-carry” basis, a temporary concession that allowed President Roosevelt to sell goods to belligerent countries if they came prepared with the funds required to purchase their goods. (Hund) When President Roosevelt saw that France and Britain were losing the war, he implemented other provisions to the Neutrality Acts to assist the Allied countries including sending supplies that were designated as “surplus”, lifting the military aid embargo and allowing free trade of any military goods with Allies. (Eleanor Roosevelt Papers Project)
In order to create support for sending military supplies to the Allies, Roosevelt delivered a speech in which he declared that America should be “… the great arsenal of democracy…” (Roosevelt) It was a call to action for industries to produce as many military munitions as possible to support the Allies. “We must use the weapons from the arsenal of the democracies where they can be employed most effectively…” (Lend-Lease: Its Origin and Development: Part I.) By the end of 1940, after President Roosevelt realized the British, along with other bankrupt European countries, could no longer pay for supplies, he proposed the Lend-Lease Act. The Lend-Lease Act allowed Roosevelt to sell supplies that would be paid for five years after the war had ended to select countries. The provisions allowed the US to offer support without entering the war until they were ready. The Lend-Lease Act produced hundreds of thousands of tanks, airplanes, and ships that were sold to the Allies. (Eleanor Roosevelt Papers Project) America gained 21.535 millions of dollars in total revenues from exports from the Lend-Lease Act. (see image 1) This burst of money helped America fund their entrance into the war. President’s Roosevelt initiatives prepared the US to what he felt was an inevitable direct participation in the war against the Axis powers (Germany, Japan and Italy).
After witnessing Germany attack many countries in Europe, the US grew its military defense budget from 2 billion dollars to 10 billion. President Roosevelt did this as precautionary measure against the possible threat of Germany waging war against them. He feared that if Germany armies took over Europe, the United States would be next. (End of the Great Depression) The US entered the war in December of 1941 after the attack on Pearl Harbor. American leadership in weapon technology and innovation of battle strategy secured Allied victory over the Axis in both the European and Pacific theatres.
World War II unleashed a fight for air control making air warfare a major player in all theatres and a critical component leading to Allied victory. Lockheed Company, an American aerospace company, answered the aerial demands of the war. They were asked to build an American aircraft that could destroy the enemy. Lockheed created and delivered the Hudson to the Royal Air Force to look for German and Japanese submarines. It carried a bomb bay and three machine guns. (Shea) Next came the P-38 Lightning. It was the most capable fighter plane in the war. It flew 100 mph faster than any other plane, had four 50-caliber guns and a 20-mm cannon. It doubled the range of any other fighter, and it had a higher carrying capacity compared to most bombers. Lockheed produced 10,000 P-38 Lightning bombers which were used in every theatre of the war. Other American companies like Studebaker and Wright built engines for heavy bombers like the B-17. Another company, Nash-Kelvinator, became the largest producers of helicopters during the war. They created the R-6A Hoverfly II which was the most advanced helicopter designed up until then. (Shea) Aside from aviation technology, the US also developed anti-aircraft weaponry.
Anti-aircraft artillery required a fuse to detonate and up until World War II they were two types: timed and contact fuses. Both fuses were relatively limited when it came to hitting a target aircraft. The timed fuse had to be calculated and set beforehand. The slightest error would make the shot ineffective. The contact fuse, as the name implies, had to hit the aircraft to be effective. This meant that fast moving targets were near to impossible to hit. John Hopkins University went to work to create a fuse that would correct the shortcomings of the old technology. They created the proximity fuse which allowed the shell to detonate in the air when it detected a nearby plane. The USS Helena used the new technology when it found itself under attack by a Japanese dive bomber. The bomber was destroyed with only two rounds. The old technology would have required thousands of shots before one shot landed. (Smithsonian) Charles Stark Draper built another revolutionary anti-aircraft instrument at the MIT Instrumentation Laboratory and named it the Mark-14 Gunsight.
The “Shoebox”, as it was nicknamed, allowed for navy anti-aircraft gunners to follow the fast-moving enemy planes with ease. The USS South Dakota used it successfully by shooting down multiple Japanese Kamikaze. Many people credit the advances in aviation and anti-aviation as the most important factors in securing Allied victory. While aviation played a critical role in the war effort, the true power of their attacks came with strategic bombing.
Aviation’s success can be attributed to the bombing strategies and types of bombs employed throughout the war. In the European theater, the US originally used “precision bombing”. They had bombers fly at extreme altitudes and attempt to hit a specific target. The attempts were shown to be extremely ineffective because what worked during practice could not be reproduced in true combat. In practice, the planes flew at low altitudes, dropping only one bomb each time they passed over the target. In real war, these practices were impossible because planes had to fly at extreme altitudes under constant enemy fire and often missed the target. (Pisano) Since precision bombing was not as effective as planned, the Air Force had to resort to what was called “area bombing”. Area bombing was the indiscriminate targeting of a large area that had a strategic target. Even though it was aimed at a strategic target it often resulted in many civilian casualties. According to the U.S. Strategic Bombing Survey approximately 485,000 residential buildings were destroyed and 415,000 sustained significant damage. In terms of people there were an estimated 305,000 German deaths and 780,000 people were wounded. (Pisano) Area bombs were effective in wiping out their target even if it came with a large death toll.
The impact of strategic bombing in Europe may have seemed horrific but it caused only a fraction of the devastation that occurred in Japan. By then, US had switched strategies to night-time attacks at a low-altitude with incendiary bombs, a special type of bomb that contained a highly flammable gel called Napalm. Cluster bombs, which were made up of many small incendiary bombs, were launched over large areas destroying strategic targets and large civilian residential areas equally. (Duus) The worst aerial attack in history occurred on March 9th, 1945. In the March 9-10 raid, as it was named, 339 B-29 bombers destroyed the Shitamachi district, a quarter of the city or sixteen square miles. The district had many small workshops that were supplying large munition factories. In two days, it was estimated that around 330,000 to 400,000 people were killed, approximately one million were injured, and another million lost their homes. On May 25, the US Air Force unleashed the power of incendiary bombs with a second raid on Japan. They used 3,200 tons of incendiary bombs and destroyed another 19 square miles. (Duus)
While over a dozen cities in Japan were being obliterated using incendiary bombs, various cities around the U.S. were involved in a new effort called the Manhattan Project. Leo Szilard, a Hungarian physicist, had realized ten years prior to the war of the potential creation of the atomic bomb. In 1939, he and Albert Einstein wrote a letter to the U.S. warning them of this possibility. It was not until after the attack on Pearl Harbor that the Manhattan Project was given the green light it needed to come to fruition. (Lerner) Facilities across the U.S. were selected. The facilities all had different tasks ranging from plutonium and Uranium refinement, to creation of nuclear reactors. The uranium bomb was designed first and was produced under the code-name of Little Boy. Little Boy was carefully loaded onto the B-29 “Flying Fortress”. Once in Hiroshima, it was released above the city, killing 260,000 people after two days and destroying 90% of Hiroshima. They then designed the second bomb, a plutonium bomb named “Fat Man”. Fat Man was dropped three days after Little Boy and while it missed its target by over a mile, it destroyed half the city of Nagasaki and killed or injured over 65,000. (Lerner) Bombing was credited with ending the war in the Pacific but it could only go so far in the European theater without the power of ground units.
The U.S. Armor units during World War II were a major force but their true power only developed later in the war. The first tank to see combat was the M-3 Lee/Grant. After witnessing the power of the German tanks, specifically the Pzkw IV, the U.S. feared that any German tank was strong enough to destroy their armored technology. They created the Grant as a result of fear and desperation. The Grant had a tall unwieldy frame with a 75 mm cannon and was substandard compared to its rival, the Pzkw IV. Its tall, awkward frame made it slow and bad at maneuvering, while the 75 mm cannon was simply not strong enough to break the Pzkw IV’s armor. The Grant also had a very light armor. It could be destroyed with only one shot. (Johnson) Its failure made the U.S. realize that it needed a more modern armor which resulted in the M-4 Sherman. The Sherman was not particularly that much better than the Pzkw V, or the new Panther and Tiger tanks. The Sherman’s 76 mm cannon could not consistently break the frontal armor of the Panther without special armor piercing rounds.
Similarly to the Grant, its armor could only withstand one shot until it combusted. Its flammability earned it the name “Ronson Lighters” because of the Ronson lighter company’s slogan “It lights ever time!” (Johnson) In spite of its unfortunate nature, the Sherman was still an instrumental weapon in winning the war. Most of its advantages were that it was significantly cheaper and easier to make. Its design was also simple allowing for many different variations to be made very quickly. Throughout the war the US produced 50,000 Sherman tanks compared to the 7,400 Panthers and Tigers Germany produced. Many predicted the Sherman would lose against the Panther but that was not its primary focus. The Sherman was made to help infantry. As the fastest tank, at the time, it would quickly flank the enemy giving the infantry an opportunity to attack. (Johnson) The adaptability of the Sherman tanks let them traverse many different types of soft terrain that the German tanks would sink in. As important at combat tanks were during the war, the U.S. knew it also needed other types of quick vehicles.
With demands for greater speed, the U.S. army requested a vehicle that would give them the lightweight, all-terrain, fast speed reconnaissance force they needed to counter the German technology. The result was a jeep. It was small, could carried 4 people or 500 pounds of cargo, reached speeds of 65 mph and was sturdy and versatile. As war correspondent Ernie Pyle would say, it was “as faithful as a dog, as strong as a mule and as agile as a goat.’ (Holloran) The jeep served in every theater during the war. It was used by all U.S. military forces, as well as by British, French, Russian, Australian, and New Zealand armed forces. Their demand was so high that Willys-Overland, the company originally contracted to build them, could not keep up so the Ford Company was also contracted to build them. At the end, Willys produced 363,000 Jeeps and Ford produced 280,000. (Shea) What made the jeeps so useful is that they could not only traverse tough terrains including snow but could transform and carry out many tasks. From carrying anti-tank guns to serving as an ambulance, the jeep could do it all. Many regard the jeeps as indispensable due to this versatility and hence why it is often regarded as critical to winning the war.
Allied success during World War II might not have been possible without the strength of the new American military technologies. Each technology advance played a distinct and significant role in the victory of the war. While some of the technologies were developed prior to the war and tweaked or improved during the war, others were developed in response to the needs of the war as it was taking place. Some were created towards the end of the war and many have contributed to the technology of today. Aviation saw some its most critical advancements in the design of fighter and bombers with technical refinements not seen before then. Those technologies that created a more advanced aircraft also opened the door to different bombing strategies each more effective than the last from precision to aerial to the dropping of the atomic bombs. American ground vehicles were not far behind in contributing to the war’s success and while they started out weak, they played a major role in securing victories across Europe. Ultimately, the inventions and technological advancements developed in the U.S. and given to European forces changed warfare and ensured victory for the Allies.
