The Frenchtown Historical Foundation was founded in 1993 by representatives of the Confederated Tribes of the Umatilla Indian Reservation, and descendants of French-Canadian fur trappers who arrived in the region before the 1836 arrival of Marcus and Narcissa Whitman. According to their mission statement, the purpose of the Frenchtown Historical Foundation is "the preservation and interpretation, through research, signage, and educational outreach, of sites related to a 19th-century community of Native American, French Canadian and métis families in the Walla Walla Valley."

The initial goal of the foundation was to maintain the sites of the old Saint Rose of Lima Mission Church and the Frenchtown Cemetery. In 2005, the foundation acquired the land of the Historic Frenchtown Site, which was also the site of the longest known battle in Washington history. The project was spurred on by the planned widening of Highway 12, and resulted in frequent communication and partnership with the Washington State Department of Transportation. In 2006, the Foundation began working on developing the property as an educational historic site, and they were also allotted a grant from the American Battlefield Protection Program. This grant funded an archaeological dig through the National Park Service, and resulted in the discovery of several musket balls from the Battle of Walla Walla.

In 2008 they received a grant through the National Scenic Byways Foundation, and on July 6, 2011, the 200th anniversary of the fur trade in the Columbia Valley region, the site officially opened. One of the Foundation's most recent major projects was the 2016 acquisition, restoration, and preservation of "the Prince's Cabin," the oldest known cabin in Washington state.