It is a High Victorian Gothic stone structure, built in 1871–73 to a design by Leopold Eidlitz, with numerous additions.

The building was listed the National Register of Historic Places on August 13, 1981, for its architecture and its role in the city's development.

The older section is a built out of granite, and is 2+1⁄2 stories in height with High Victorian Gothic styling.

[2] The main building design was by Leopold Eidlitz, a prominent New York City architect, and it was completed in 1873.

In 1891 the school began accepting tuition-paying out-of-town students, and its success prompted several rounds of expansion.