Paulinus Mayhew Foster was born in Readfield, Maine on January 1, 1811.
He studied law in both Anson and Hallowell, having as his instructor in the latter place future Governor, Samuel Wells.
After being admitted to the Somerset County Bar he practiced law for twenty-five years in Anson, moving to Richmond, Maine in 1860.
According to an obituary published the year he died, he was an active Democrat all his life and filled several political posts.
He was elected to the State Senate in 1848 and 1849, serving as President of that body in 1850.
He died in Richmond, Maine in 1861 at the age of fifty, probably from rheumatic fever.