 Foster would become known as the "Father of Tukwila" and represented King County in the Washington Territorial Assembly for 22 years.Today, the site of Foster's home on the banks of the Duwamish River is part of Fort Dent Park, which also served as a military base during the 1850s Indian Wars.Foster's name is memorialized in the Foster neighborhood of Tukwila, where Foster High School is located.