Homes for sale in
Winthrop Harbor.

The land that became Winthrop Harbor was first eyed for development in 1883 by J. H. Van Vlissingen, but nothing came of it. In 1899 the Winthrop Harbor and Dock Company purchased over 2,000 acres just south of the Wisconsin state line with the intent of building an industrial harbor town. The village incorporated in 1901, a year before its southern neighbor Zion was founded by John Alexander Dowie as a religious utopian community. The harbor and industrial vision never materialized at scale, and Winthrop Harbor settled into the role of a small lakefront residential village through most of the twentieth century.

The defining modern event for the village was the 1989 opening of North Point Marina, a State of Illinois facility built on what is now considered the largest marina on the Great Lakes with roughly 1,500 slips. The marina effectively gave the village the identity its founders had imagined nearly a century earlier, just recreational instead of industrial. Spring Bluff Forest Preserve and the adjacent North Unit of Illinois Beach State Park preserved much of the surrounding shoreline as protected dune and wetland habitat, locking in the village's small footprint. Today Winthrop Harbor remains primarily single-family residential, with the marina, the lake, and the state park drawing most of its visitor traffic.