The technological advancements achieved during World War II made it far different from any war that came before it. The brutal trench warfare that was so important during World War I gave way to new methods of fighting, including large-scale artillery barrages, advanced air combat, and oceans littered with massive fleets battling it out for naval supremacy. There are plenty of reasons why the Allies prevailed over the Axis powers—here are just 11 of them.
1. B-17 Flying Fortress
When Boeing first began manufacturing its so-called Flying Fortress, the B-17, on a large scale, the massive plane featured nine machine guns and could carry 4000 pounds of explosives. Its capacity for destruction only grew as the war dragged on; later B-17 models were equipped with more than 10 .50 caliber machine guns and nearly 10,000 pounds of bombs. The Boeing B-17 Flying Fortress gave the Allies a distinct advantage from the skies. During the war, the B-17s were aided by gun turrets across their frames, providing fire support so they could drop their payloads of bombs in both the European and Pacific theaters. Around 640,000 tons of bombs were dropped on Nazi Germany by B-17s during the course of the war. Though the planes were large and heavily armored, they had a top speed of over 280 miles per hour, which was deceptively fast for something that size at the time.
2. M4 Sherman Tank
The M4 Sherman wasn't as powerful as many of the enemy tanks on the battlefield, but America's ability to mass produce them resulted in the manufacture of nearly 50,000 between 1942 and 1946. (The military emphasized speed and efficiency while designing the tanks, which critics point out came at the expense of indestructibility.) Armed with a turret gun, support machine guns, and a five-man crew, the M4 allowed Allied troops to fight their way deep into enemy territory. Other modifications were added throughout the war, most famously the "Donald Duck" model used by the British that allowed the tank to float to shore during the Normandy landings.
3. Mk2 Fragmentation Grenade
The standard issue U.S. hand grenade—known colloquially as the pineapple grenade—was everywhere during World War II. Not only was it simple to use, but its unique casing would break into a thousand pieces of fiery shrapnel upon exploding. The grenade was lethal within a 30-foot blast radius, but it could wound anyone unlucky enough to be caught in a 50-yard radius. It had a fuse time of 4-4.8 seconds, giving soldiers the option of either throwing immediately or holding on for a second or two to reduce the enemy's ability to throw it back.
4. Radio Proximity Fuze
Before the invention of the radio proximity fuze—now known as the VT fuze—shooting down an enemy aircraft was wasteful and impractical. It would often take an average of 2500 rounds to bring one down—if you brought it down at all. With the radio proximity fuze, that all changed. Instead of having to make direct contact with a fast moving target, a rocket or torpedo armed with a proximity fuze would use a radio signal to detonate whenever it detected a craft was nearby. The resulting explosion would besiege an enemy craft in flak and debris without having to be directly on target. This drastically cut down on the waste and exhausting effort of contact and timed fuzes.
5. M2 Browning
With the ability to punch through the hull of a ship and bring down enemy aircraft, the M2 Browning .50 caliber machine gun was a staple during the war. Almost 2 million M2s were produced for the troops, and with good reason: They were among the most versatile weapons available, arming soldiers on land, in the air, and on the water. The weapons could fire 550 rounds per minute and had a range of over four miles [PDF]. The Browning's destructive potential and dependability has made it a constant presence in militaries worldwide for decades—in fact, it's still in use today.
6. M1 Garand
Described as "the greatest battle implement ever devised" by General George S. Patton, the M1 Garand was the first self-loading rifle to become standard issue for the United States. Used in every branch of the military during World War II, this semi-automatic rifle gave Americans the ability to fire off eight rounds without having to deal with a clumsy bolt-action reload design. This helped American troops improve their aim and efficiency during combat, which would prove to be an invaluable advantage over the Axis powers. After World War II, the M1 served the United States through the Korean and Vietnam Wars, and into the late '70s.
7. The M1 Thompson
Originally designed for trench warfare in World War I, the M1 Thompson—a.k.a. the "Tommy Gun" or "Chicago Typewriter"—became infamous in the 1920s and '30s for being the weapon of choice for police and gangsters during Prohibition. However, this submachine gun gained its respectability back on the battlefields of World War II. With a 30-round capacity and a firing rate of 700 rpm, the Thompson proved to be effective, lightweight, and easy for troops to use. Over 1.5 million Thompsons were distributed during the war, but they didn't just arm American troops; they were also sent to British and French troops as a part of the Lend-Lease Act.
8. KA-BAR Knife
At the time the United States entered World War II, the military was still using weapons that had been in use during the First World War, including long trench knives. The military soon realized that what worked during trench warfare wasn't suited for this new style of battle. In 1942, the Union Cutlery Company proposed a new combat knife design for the United State Marines, which was accepted and soon became standard issue for everyone in the Corps. With a better grip for close combat situations, and a sturdy 7-inch blade, the knife—which came to be known as the KA-BAR—eventually became the standard for every military branch. It also served as an all-around tool for opening up ammunition crates and cutting through other obstacles.
9. M101 Howitzer
The United States military's emphasis on artillery during World War II meant it needed a dependable, lightweight howitzer for the field in both the European and Pacific theaters. The M101 Howitzer rose to prominence not because of what one could do on its own, but what a line of these artillery pieces could do when concentrating their firepower. They provided support for ground troops on foot and in vehicles, and with a range of nearly seven miles [PDF], the M101 proved to be a vital weapon for long-range attacks.
10. The Bazooka
Cited by President Dwight Eisenhower as one of the keys to the Allied victory, the bazooka was a vital tool for troops going up against fortifications and tanks across Germany and the Pacific. Despite its ability to punch a hole in enemy armor, the bazooka was most effective when it was strategically fired at certain weak points of a tank, rather than used for head-on assaults. A standard bazooka had a firing range of about 300 feet and was lightweight and easy to mass produce. During the course of the war, there were nearly half a million bazookas produced for combat.
11. ATOMIC BOMB
Any talk of weapons that won World War II begins and ends with the atomic bombs dropped on Hiroshima and Nagasaki in August of 1945. The two bombs killed an estimated 200,000 people—many immediately, but thousands of more later on due to radiation exposure. Work on the bombs began in the U.S. in 1939 under the name The Manhattan Project; the program was so secretive that President Harry Truman didn't even know of its existence until he took office in 1945, after President Roosevelt's sudden passing.
Despite the horrifying effects of the bombs, the United States justified their use by arguing that, however brutal, they would bring about a swift end to the conflict and actually save more lives in the long run. Although other countries have produced and tested their own nuclear arsenals in the decades since, the bombings of Hiroshima and Nagasaki were the last time a nuclear weapon was used in combat.