Who was allowed to volunteer to be soldier during World War 1?

Why is propaganda so important during times of war? What was the name given to the group of ex World War 1 soldiers who marched on Washington to demand early payment of their pension bonuses? The Know-Nothing party was strongest during which decade? The Peace Treaty of 1766 ended the Indian attacks led by? What was the basic issue that led to World War 2? How many sailors died on the uss nimitz? How thick was the pershing tanks armor? How many slaves were owned in Kansas in the year 1860 as ascertained by the Census of that year? How did North America become vulnerable to attacks after World War2? Why was Francisco Franco so famous for? What effect did new weapons have in ww1? What was written on the front of a gas mask box? One way to remember the instruments of national power is by using the acronym? Who had the second nuclear bomb? Who has the US Army fought against? Why cold war affected Cuba? What are the three main causes of the civil war? What ships served at d day? How old was Alvin York when he was in the Civil War? What as the most important invention that was in World War 2?

Who was allowed to volunteer to be soldier during World War 1?