If you're a fan of the TV series "Downton Abbey," you know how horrible of a slaughter World War I was. It was so bad, in fact, that after the U.S. entered the war in 1917, about 21,000 young men sought legal exemption from the military draft as conscientious objectors (COs).
They were compelled to go through boot camp anyway, but in the end, about 4,000 of them did not have to serve in combat. Some of the reluctant soldiers were allowed to serve in different ways, while others were granted deferments to go back and work on farms [source: Patterson].
Other men simply went to prison. When a conscientious objector named Evan Thomas refused an order to eat during a hunger strike, for example, a military prosecutor sought to have him executed, arguing that failure to punish such cowards would threaten the U.S. government's survival. Instead, Thomas was sentenced to 25 years — though eventually, he was released early thanks to a legal technicality [source: Thomas].
During World War II, even more Americans — more than 72,000 — sought CO status, and another 6,000 were jailed for refusing to cooperate with draft boards at all.
But the U.S. government didn't treat resisters as harshly as it had in the previous conflict. Many were allowed to serve in the Civilian Public Service, where they could work on conservation projects or as firefighters. Some even showed their bravery by serving as guinea pigs in medical experiments
Similarly, during the Korean War in the 1950s, conscientious objectors were allowed to do construction and farm work instead of taking up arms [source: Yoder].
During the Vietnam conflict in the 1960s and early 1970s, it became more difficult to seek CO status, because of changes in the law that excluded anybody who didn't object to all wars for religious reasons. As a result, while 170,000 young men were granted CO status, tens of thousands chose either to go into hiding or flee to other countries [source: Yoder].
Even after the U.S. stopped military conscription in 1973 and switched to an all-volunteer military, some members of the service occasionally refused to participate in wars. During the U.S. occupation of Iraq in 2004, for example, 110 soldiers filed paperwork to become COs. Half had their requests granted. Some of those rejected went into hiding, while others were court-martialed and served jail time [source: Associated Press].