Host to Washington's army for nine months during the Revolution, Montgomery County was the site of early lime, paper, iron and textile industries, as well as canal and railroad systems. Montgomery County was set off from Philadelphia County on September 10, 1784. Almost one hundred years later, spurred on by the approach of the county's centennial, a groups of prominent citizens met on Washington's birthday in 1881 to form a historical society and to plan a celebration. On May 11, 1883, the flourishing historical society was chartered to preserve the civil, political, and religious history of the county and to promote the study of history.
The Headquarters contains a research library and archives, changing exhibitions, collection storage and meeting space. Special events are held throughout the year.