Montgomery County (population 750,097), just to the northwest of Philadelphia, was part of William Penn's original land grant in Pennsylvania. Pioneers settled the lower half of the county by the end of the 17th century, followed by waves of English, Swedish, Welsh, German, Scotch-Irish, and Dutch immigrants.
By the mid-18th century, the remainder of the county was settled, and the area became independent from Philadelphia County in 1784. Largely agricultural, during the Revolutionary War American forces spent nine months quartered in Montgomery County, including the famous winter encampment at Valley Forge.
The earliest industries were mining operations, and iron forges and furnaces were active before and during the American Revolution. A new canal system in the first quarter of the 19th century was followed by railroads and the development of new population centers as well as industry. By the 1890s, a broad array of mills and other manufacturing had developed. Its proximity to Philadelphia also led to the establishment of many fine country estates by prominent business families.
Valley Forge National Historical Park is the county's premier heritage attraction, and a new National Center for the American Revolution is under development at the site. The center will be the first comprehensive museum devoted to interpreting the American Revolution.
The Valley Forge Convention and Visitors Bureau has launched numerous regional marking programs such as the recent "Patriots or Traitors" collaborative program, which linked 20 historic sites through a series of special events and coordinated interpretation.
In addition to its Revolutionary War resources, Montgomery County has many other historic sites. The county operates five historic sites, including Mill Grove, first home of John James Audobon; Pennypacker Mills, early 20th century estate of Governor Samuel W. Pennypacker; the Peter Wentz farmstead, where George Washington planned the Battle of Germantown; Pottsgrove Manor, 1752 home of ironmaster John Potts; and the 1767 Sunrise grist and sawmill .
The county's Department of History and Cultural Arts also produces a lengthy annual series of summer educational programs and exhibitions. Twelve county municipalities have historic preservation ordinances, and six are Main Street Communities.
Designated a Preserve America Community in August 2004.