Not a complete list of course, but some reasons,not in any order would be : Patriotism, adventure, to escape un-employment,escape parental rules,or boredom,need for excitement,chance to travel the world, even in some cases escape the courts and police. I think the majority were to fight those who attacked us.
They wanted to help their country and their allies.
they signed up at the recruiting station, as they do today
The Judge ordered the young man to enlist in the army as part of his sentence for the crime of burglary.
Some countries did have conscription (aka "the Draft"), and required young men to enlist. Other young men signed up voluntarily.
they thought it would not last long and it would be quite fun
Nationalism plays a big part in a soldier's desire to join the war. The soldiers wanted to be able to say they fought for their country. Also, before WW1 started they thought it was only going to last a few months. however, they were wrong and the war lasted a couple years.
The marines will take people of different ages. In order to enlist to become a marine you should be between the age of 17 and be no older than 29. It is possible you can enlist when you are over 29 but you will have to submit a waiver.
Anne change from a young girl to young women during World War two.
At the beginning of World War Two (and before) men willingly enlisted. The government put the draft in place eventually. The draft weeded out those who were not eligible to serve and those who could. Men continued to enlist willingly though. Some young men who were only 17 uncommonly and fraudulently enlisted too by telling the recruiters they were 18 and often showed false papers.
In the US, the military put up posters asking for volunteers. They also set up recruitment centers for young men to enlist.
Mary Sophia Stephens Sims has written: 'Women and leadership' -- subject(s): Leadership, Women, World Young Women's Christian Association 'The YWCA, an unfolding purpose' -- subject(s): History, World Young Women's Christian Association
They thought it would be an exciting adventure, and it had been decades since Europe had a major war.