Montgomery County was incorporated in 1784 from a portion of Philadelphia County. The county's early settlements and land grants date back to the founding of Pennsylvania in the 1680s. During the American Revolution, Valley Forge and the Whitemarsh encampments took place here, making Montgomery County nationally famous. Philadelphia's influences in art, culture, and architecture have had a lasting impression in the county. The postcards and descriptive text in Eastern Montgomery County illustrate the rich historical heritage of the area, dating back from its very beginning up to the mid-twentieth century.