A large area covering what is now Caledonia was part of what is now Mumford.

John McKay purchased 200 acres from Charles Williamson, land agent. This included a grist mill-The so called second emigration came in 1803 consisting of about 30 people. The first schoolhouse west of the Genesee River was built in that year.

Donald McKenzie became the first clothier west of the Genesee. He later built a woolen mill and later a saw mill. Around 1808 to 1810 the settlement was known as McKenzie's Corners. Later it was called Slab City because of the materials used in the construction of the first houses. In 1812 a mail route was established between Canandaigua and Batavia. Up until this time Mumford residents had to pick up their mail in Canandaigua.

Oliver Allen and William Remington formed a partnership and rented  McKenzie'swoolen factory.

A survey was compiled to establish property lines. At this time the hamlet began to be called Mumfordville for Elihull S. Mumford. Later on the "ville" was dropped and it has remained Mumford ever since.

Philip Garbutt built a plaster mill on George street.

The post office was ofically established.