Question

Before his appointment to the vice presidency, gerald ford--who became president on richard nixon's resignation and was the nation's first non-elected vice president--had been

Answer 1

It was John Tyler.

 Tyler's opponents regularly called him "His Accidency" and addressed correspondences to him as "Vice President" or "Acting President" (letters which he returned unopened).

When his term ended in 1845, he did not seek election.