Rockland Harbor is protected by a granite breakwater that was built between 1888 and 1900, transforming the harbor from a dangerous area to a safe haven for ships. The lime extraction, cement production, and granite quarrying industries, critical to Rockland’s economy, were centralized at the harbor through the end of the nineteenth century and into the twentieth century, at which time Rockland was the fourth busiest port along the east coast. The shipbuilding industry also thrived amongst the harbor’s 44 wharves, where ships bringing in foreign goods, lumber, and coal would dock. Rockland Harbor has remained a working waterfront into the 21st century.

The caption reads, "Rockland Harbor from Docks, Rockland, Maine."

The Tichnor Brothers printing company published this type of postcard circa 1938.