The direct cause of WWI was the assassination of Archduke Franz Ferdinand at Sarajevo on 28 June 1914.
Wanted higher minimum wage, an extension on social security benefits, fair wages for women and men, and improvements on the welfare program, health care, improve the economy, improve education, win the space race
During American involvement in WWII, propaganda was used to support the war cause. I hope I could help. Have a wonderful rest of the day.