Logan Square is anchored by the Logan Square Boulevards District, which was listed on the National Register of Historic Places in 1985 and became a Chicago Landmark on November 1, 2005. Encompassing 2.5 miles of the larger Chicago boulevard system, this district includes Logan and Kedzie Boulevards, and sections of Humboldt Boulevard, as well as Logan Square proper (the Square) and Palmer Square.

The neighborhood features a distinctive and remarkably intact group of single-family houses, small flat buildings, larger apartment buildings, and small-scale commercial, institutional, and other buildings built between 1880 and 1930 that reflect fine detailing and craftsmanship seen in such building elements as cornices, porches, windows, and doors, the overall collection of stylistic examples, ranging from excellent to modest, illustrating (among many architectural styles) Second Empire, Queen Anne, Richardsonian Romanesque, Classical Revival, Prairie, and American Four-Square influences, and for the high quality of materials including brick, stone, wood and metal.”

The first owners on the boulevards were well-to-do, but not so wealthy that they could replicate the mansions they envied in the Gold Coast, or along Prairie and South Michigan Avenues. Still, when they hired architects, they expected them to incorporate many of the same elements into their projects. Referred to as “stylistic eclecticism,” many homes and flats feature an assemblage of corner towers and turrets, crenellated parapets, dormers, pitched gable roofs, and projecting porches — with classical details and ornaments such as bay windows, columns, balustrades, brackets, and pilasters. The architects didn’t seek any consistency of style; it seemed that symmetry was outlawed and flats were made to look like single-family homes.

Architects then transitioned and translated the forms and exuberance of Logan Square’s greystones into brick. To do so, they used contrasting zones of colored brick and brick texturing. Stone was used to accent for window surrounds, cornices, and other decorations. Symmetrical designs began to appear with the use of Prairie, Classical, and Tudor Revival styles.

The designers of the houses on the boulevards are too numerous to mention; more than 75 can be identified, and many more would be involved with the surrounding blocks. A few stand out, having designed more than a dozen structures. Charles F. Sorensen, a Danish immigrant, designed residences in timber, stone, and brick, as well as churches and stores, between 1890 and 1915. Brothers Fred and John Ahlschlager, who grew up on a farm in Mokena, Ill., designed stores, apartments, and some of the biggest houses on Logan Boulevard. The partnership of Worthmann & Steinbach (John Steinbach, in particular) was responsible for designs of residences, flats, at least one major commercial structure, and several major churches.