CarpaDM,

FDR served as asst. secretary of the US navy, was in charge of decommissioning armed forces after WWI and founded the United States Navy Reserve. Clinton was commander in chief of the Arkansas National Guard. Obama is the only one with zero military experience.  However, all of them had extensive governing, legal and legislative experience prior to their role as POTUS.

Trumps' only experience was his "personal Vietnam" avoiding STDs and of course some good old draft dodging