Established as Provisional Government Park in 1913 to commemorate May 2, 1843 meeting of the "Inhabitants of the Willamette Settlements" to organize a civil government. The Organic Act, adopted July 5, 1843, was a Provisional Constitution for the Oregon Country, the first American Government on the Pacific Coast.

"Champooick," a Calapooya Indian Village was first visited by hunters and fur traders of Astor's Fur Company in 1811, and by 1831 the first farms were settled on French Prairie to the southwest by retired French-Canadian employees of the Hudson’s Bay Company. Because of its accessibility the company built a grain warehouse at Champoeg in 1841. The first formal organization of Champoeg Town began with the survey made in 1852 for Andre Longtain and Robert Newell. With the flood of 1861 most of the town buildings were swept away, and in 1892 the townsite was