* The Potomac River is first sailed by a European in 1631, when Henry Fleete sought gold in the then-named Patomack River. He anchors at Great Falls.
* 1700s: Roads such as River Road and Falls Road are first established as Native American trails
* 1812: Captain John’s meeting House becomes the Cabin John area.
* Glen Mill Road is named after Glen Mill, where gold was first found in the county. The mill burned down in the 1950s.
* Rockvilleias the seat of the County Government until 1801.
* Montgomery County is named after General Montgomery.
* 1828, July 4: John Quincy Adams breaks ground for the C&O Canal.
* 1861: Montgomery County is occupied by Federal Troops; Confederate flags prohibited.
* 1861, July 7: Skirmish on the Great Falls, where Union troops, outnumbered, hold back Confederate soldiers.
* 1867: Gold discovered near Great Falls, and soon thereafter Potomac becomes a center for gold mining for the entire state.
* Post Civil war: County population increases, due to the canal, the Great Falls aqueduct, and the discovery of gold.
* 1940s and 1950s: Farms become less productive, prompting new housing developments.
* 1960s: Potomac’s housing developments accelerate dramatically and experience a 287 percent population increase.
* 970s to present: Montgomery County’s population increases at a rate of about 30 persons a day, and Potomac’s population rises from 30,395 to 80,155. As suburbanization spreads, the area’s land continues to be subdivided into residential developments.