At the age of only nineteen years, he became the initial editor of the Pittsburgh Morning Chronicle in company with publisher Richard G. Berford.
Foster was a social and moral crusader from his earliest editorials, targeting such vices as drunkenness, corner loafing, and desecration of the Sabbath.
[3] A staunch opponent of slavery, Foster was nominated by a Free Soil Party convention in late 1852 for Mayor of Pittsburgh.
[8] Foster served as an officer in the Civil War, eventually attaining the post of district Provost Marshal.
[11] Mark Twain, in his travelogue The Innocents Abroad (1869), noted with sadness the loss of the man he called "a most estimable gentleman.