Born in Ireland,[1] Finley moved to a 287-acre (1.16 km2) farm in Fayette County, Pennsylvania, near Uniontown.
[2] Elected a justice of the peace in 1784, he went on to become county commissioner in 1789, and a member of the Pennsylvania House of Representatives and Senate.
Finley is also credited with designing and constructing a chain suspension bridge across Dunlap's Creek in Brownsville, Pennsylvania, in 1809.
In 1820, however, the bridge collapsed under a heavy snow combined with the loads from a six-horse wagon team.
Finley patented his system in 1808 and also published a paper on the principles of the deck-stiffened suspension bridge.