Ashcroft Manor was named by two brothers, Clement Francis Cornwall and Henry Pennant Cornwall, after their birthplace in Gloustershire, England. Both were graduates of Cambridge University and arrived in BC in 1862. Clement was a barrister-at-law, and appointed member for Yale, Hope and Lytton in the Legislative Council of BC in 1864. After Confederation, he was appointed to the Senate in Ottawa and in 1881 became Lieutenant Governor of BC.

On their ranch the Cornwalls raised wheat and built a grist mill. They tried to live the life of English gentry and even imported foxhounds from England for hunting coyotes. Clement Cornwall pursued the sport for 20 years and declared that the coyote was greater sport than the fox because of its superior stamina.

The town of Ashcroft lies on the east side of the Thompson River, across from Ashcroft Manor and Highway 1. At one time the Cornwall's ranch did straddle the main road to the Interior. The town was formed when the Canadian Pacific Railway was built through the area in 1884. Because the new town was called Ashcroft the Cornwalls added "Manor" to their ranch's name in order to create a distinction between the two. After the CPR was completed much of the Cariboo Wagon Road to the south fell into disrepair and eventually large sections became impassable.  In order to get to the Cariboo from the Lower mainland people took the train as far as Ashcroft, then continued northward along the remaining portion of the Cariboo Wagon Road. Ashcroft effectively replaced Yale as the gateway to the Cariboo.

Ashcroft occupies the most arrid part of the Dry Belt where rainfall is only 7 inches a year. Crops can be grown only with irrigation. At one time the region was famous for its potatoes and tomatoes.

Ashcroft declined in importance when the Pacific Great Eastern took the Cariboo traffic away from the area.