World War I

In 1918 the Spanish Flu killed at least 50 million people around the world and was the second deadliest plague in history–after, well, the plague in the 1300s. But how exactly did a flu virus cause such massive death and destruction across the world?

Learn about Hitler's survival during WWI.

In a Mail Call video, R. Lee Ermey answers a question from Mark of Kansas who wants to know what was in a World War I backpack. Ermey reveals that on top of all the other hardships WWI soldiers had to endure, their backpacks proved to be another annoyance. Men from the Great War Historical Society strapped on the WWI packs and completed some drills; by the end, they definitely felt the WWI soldiers pain. The bottom section of the backpack, known as the diaper, was detachable and carried the soldiers blanket, shelter half, and shelter half pole and pins. On the belt youd find ammo, a first aid kit, a canteen cover, and a canteen and cup. Inside the flaps were a baking tin, a condiment can, and boxes of bread rations. Also inside the flaps were a towel, soap dish, shaving kit, handkerchief, foot powder, and extra socks. Attached to the outside were the bayonet, shovel, trenching tool, and a mess kit. The entire weight of the pack lies entirely on the soldiers shoulders, making it very uncomfortable. If a soldier wanted to get anything out of his pack, he would have to stop, unravel everything, get what he needs, and then pack everything back up. Due to the placement of the bayonet, most soldiers would have to have a buddy put it back for them.

In 1997 Dr.Johan Hultin excavated an indigenous village graveyard in hopes to find the cause of Spanish flu but found much more.

Marcelino Serna came to the U.S. as a undocumented immigrant, and within just a few years, became one of the country's bravest heroes.

The Harlem Hellfighters were an African-American infantry unit in WWI who spent more time in combat than any other American unit. Despite their courage, sacrifice and dedication to their country, they returned home to face racism and segregation from their fellow countrymen.

Learn about the use of poisonous gas during WWI.

Archduke Ferdinand's assassination caused the outbreak of World War I, but what caused the assassination itself? It may have been something as simple as a wrong turn.

In this video clip of History's Mail Call, host R. Lee Ermey takes a look at how gasmasks work and explains why those sold in surplus stores are not worth the money. Military gasmasks will save your life if they are made and worn properly. When poisonous fumes enter the mask it passes through a filter with a dense layer of carbon and thick padded air cleaner. It is then cleaned and provides fresh air to the soldier or person wearing the mask.

Check out six fun facts about the history of tanks.

A look back at the legacy of World War I nearly 100 years after the conflict began.

An ill-fated assault on Turkish forces leads to 500,000 casualties in World War I.

When Germany torpedoes a British passenger ship believed to be smuggling arms, anger at the resulting American deaths increases pressure on President Wilson to enter World War I.

After two years of trench warfare, the Allies attempt to break through German lines on the Western Front. The ensuing battle will last for months and result in more than one million casualties.

In the years leading up to WWI, a series of agreements between the powers of Europe helped determine where and when battlelines were drawn.

After the Spanish Flu descended on New York City in 1918, its citizens did everything they could to flatten the curve.

On November 11, 1918, World War I finally came to an end after four-plus years of combat. Armistice Day was wildly celebrated throughout the world, and in this rare footage, we see how New York, Washington D.C. and Paris took to the streets with pure joy.

Did you know that the first-ever tanks, chemical weapons and blood banks were introduced during World War I? Get all the facts behind the conflict known as the "war to end all wars."

These deadly German submarines dominated the waters in both WWI and WWII.

Thousands of miles of trenches were built during World War I and, for the soldiers living in them, their day-to-day life was nothing short of horrific.

Although best known for its role in the long slog of World War I, trench warfare actually got its start on the battlefields of the American Civil War. Find out how new weapons and technology played a part in both its development and destruction.

After the repeated sinking of American ships, the President declares war. Historic film footage shows some of the first naval battles.

German resentment over harsh peace terms leads to a rise in nationalist sentiment and the eventual rise to power of Adolf Hitler.