There's really no reason to think that something that happened a single time in over 200 years is likely to happen a second time
Ehhhh... I mean Hoover was a businessman who never held elected office or served in the military, so he basically counts.
Willkie was nominated without having ever held elected office. He was a junior officer for 2 years during WWI and left the army when the war ended, so nothing like Grant/Ike/Washington, etc. on that front.
Lincoln had only ever been elected to the state legislature.
Hoover is the closest but he was a Cabinet secretary, OP did not specify elected, just government.
Lincoln served a term in Congress
