From wikipedia - https://en.wikipedia.org/wiki/Bounty_jumper
men who enlisted in the Union or Confederate army during the American Civil War only to collect a bounty and then leave.
A month after the Battle of Fort Sumter the United States Congress passed a law allowing for bounties up to $300. The Confederate government did likewise, starting at $50 and then later in the war increased the bounty to $100.
As the typical Northern private was paid $13 a month, the bonuses were considerable.
Risky, since desertion for them could mean torture or execution, but the money was really good for the time.
Rich man’s war, poor man’s fight as it was called.
Valid for many wars before and still valid today