As a young man he had left his family because of unhappy domestic relations with his wife.
One may find in the record of his undertakings which he left in the Philadelphia Library, to be opened thirty years after its receipt, these words: "I know of nothing so perplexing and vexatious to a man of feelings as a turbulent Wife and Steamboat building." But in spite of all his difficulties Fitch produced a steamboat, which plied regularly on the Delaware for several years and carried passengers.

"We reigned Lord High Admirals of the Delaware; and no other boat in the River could hold its way with us," he wrote.

"Thus has been effected by little Johnny Fitch and Harry Voight [one of his associates] one of the greatest and most useful arts that has ever been introduced into the world; and although the world and my country does not thank me for it, yet it gives me heartfelt satisfaction." The "Lord High Admirals of the Delaware," however, did not reign long.

The steamboat needed improvement to make it pay; its backers lost patience and faith, and the inventor gave up the fight and retired into the fastnesses of the Kentucky wilderness, where he died.
The next inventor to struggle with the problem of the steamboat, with any approach to success, was John Stevens of Hoboken.

His life was cast in a vastly different environment from that of John Fitch.