There are a total of 24 Peg Leg Trinkets in Assassin's Creed 3. They are needed for the Peg Leg side mission and will unlock secret areas such as Fort Wolcott and Oak Island. The Trinkets have fixed locations and spawn at any time. The quest giver can be found at the harbor of the Homestead. Return the trinkets to him to progress in the side mission.
Find all of them to discover a secret treasure on Oak Island and some other hot loot!