The "Friendship sloop" developed in the late 1800's from "Muscongus Bay boats" of Friendship, Maine and Essex sloop boats of Gloucester, Massachusetts. Fishermen were looking for a boat that was larger and deeper than the Muscongus boat, but smaller than the sloop boats. The Morse family, at Friendship, became the leading designers and builders.

The boats were about 30 feet wide 10 feet wide and drew 5 feet of water. Gaff rigged with two headsails; the sail plan was quite large. This was necessary because of their heavy displacement. They were fitted with small cuddy cabins forward and the ballast was gravel and stones. The fisherman's catch was usually iced or salted. In the 1890's the sloops were used in the inshore lobster fishery.

Yachtsmen began using them in the 1920's. A few of them made voyages across the Atlantic. In the 1970's Jarvis Newman built fiberglass replicas. Many of these are sailing the coast of Maine, taking passengers on day trips. The "Friendship Sloop Society" holds annual races in Maine.