The Middlesex Plat Historic District is located in Des Moines, Iowa, United States.

It is part of The Bungalow and Square House--Des Moines Residential Growth and Development MPS.

The Middlesex Plat is an infill area to the east of the western developments that had been built in the late 19th and early 20th century.

The Ingersoll Run sewer line was completed into northwest Des Moines in 1907.

Those who promoted the development of the area were able to control it in order to maintain their promises to those who bought lots and the builders.

Realtor Winner and Kauffman and house builders Henry Tillia and Charles Barnes were influential in the development of the area.

[2] The Middlesex Plat Historic District is largely composed of square houses and bungalows with a mixture of a variety of subtypes.

Of the 293 properties in the district 187 are houses, of which only nine are not contributing because they were built more recently or substantially altered.

Because they post-date the period being studying they do not contribute to the historic nature of the district.