[1] Foster, along with Samuel Gompers, helped to found the American Federation of Labor (A. F of L.), was its first national secretary and president of the state chapter.
In his report to the federation's Chicago congress in 1884, Foster told the assembly, "A united demand for a shorter working day, backed by thorough organization, will prove vastly more effective than the enactment of a thousand laws depending for the enforcement upon the pleasure of aspiring politicians and sycophantic department officials," asking member unions to vote on "the feasibility of a universal strike for a working day of 8 (or 9) hours to take effect not later than May 1, 1886," ushering in the eight-hour labor-reform movement.
Foster helped to steer labor unions away from Socialist and Marxist philosophy and toward the Democratic Party.
Although he narrowly lost the election by some two thousand votes he led the ticket and had an impressive showing in Boston.
Foster also attained fame through a historic debate at Faneuil Hall in 1904 in which he engaged Charles W. Eliot, President of Harvard University, on the principles of trade unionism.