John Burt Foster was born in Petersham, Massachusetts on June 5, 1819, the son of a farmer and one of eight children.
His father having died when he was nine and finding himself in charge of the family farm at sixteen, he secured for himself what education he could in public schools and several academies in both Massachusetts and Maine.
Obviously quite shrewd and with a knack for business, Foster left the farm and clerked in a store in Athol, Massachusetts before moving to Bangor, Maine in 1837.
In 1839 he joined the firm of Howard and Jenkins in Bangor as a clerk and in five short years was its managing partner.
In 1842 ill health forced him to give up the business and at a doctor’s advice he took a long sea voyage, first to New Orleans and then to France.
He returned one year later in such ill health that he had to place himself under a physician’s care in both New York and Boston before returning to Bangor.
Upon his return to the Queen City he made one of the shrewdest moves of his life, marrying the daughter of Jacob McGaw, one of Penobscot County’s leading lawyers, a graduate of Dartmouth, a lifelong friend of Daniel Webster and one of Bangor’s early leading citizens.
From that point onward both Foster’s health and business prospects appear to have taken a turn for the better so that in the next thirty years he became a partner in several of Bangor’s lumber firms, a large real estate dealer and one of the leading underwriters of marine insurance in Maine, having founded his own company in 1851 and spending twenty years as its President.
Equally successful in politics, Foster held several posts in city government, served two terms in the Maine House in 1865 and 1866 and was twice elected to the Senate.
He was known as a sharp debater and able politician. His last active role in politics was as a member of the Executive Council in 1879, closing out a political career that began as a Whig supporting "Old Tippecanoe" in 1840.