It covers a 5-acre (2.0 ha) that is a remarkably well-preserved and cohesive residential development created as the result of one of Boston's many land-reclamation projects in the 19th century.

This area, originally salt marshes that flooded at high tide, was at first gradually filled in as the Boston Neck was widened with the construction of Tremont Street and railroad lines.

The Tremont Improvement Company acquired a remnant portion of the salt marshes by the early 1860s, and built a series of single-family row houses on the land that resulted from filling it in.

[2] The district was added to the National Register of Historic Places in 1996[1] and is a pending Boston Landmark.

The nearby intersection of Tremont and Hammond streets was dedicated as Frederick Douglass Square in 1917, giving the district its name.