Bredin graduated from Pratt Institute, New York, in 1898. From 1900 to 1903, he attended the New York School of Art, where he studied under William Merritt Chase, Frank V. DuMond and J. Carroll Beckwith. Among his classmates were Edmund Graecen, Robert Spencer and Charles Rosen, who became lifelong friends. With Graecen, he conducted an art school in Chase's old studio. Bredin also studied at the Pennsylvania Academy of the Fine Arts, under Thomas Eakins and Robert Henri.
In 1914 Bredin won an important prize, the second Hallgarten, in the Academy annual. In the same year the artist married Alice Price, sister of Frederick Newlin Price, the noted art dealer and critic. The couple traveled to France and Italy. They returned within the year and settled in New Hope, Pennsylvania. Bredin became an active member of the area's flourishing art colony, whose numbers included Rosen, Spencer, Daniel Garber and Edward Redfield.
His World War I service was in the Foyer du Soldat, a social service unit of the French army, which he joined in 1918, serving as a regional director until 1919. He revisited France in 1929, fulfilling a portrait commission from Swarthmore College.
Known as both a portraitist and landscape painter, Bredin also executed murals; five-panel mural for the New Jersey State Museum, was completed by March 1928. He also maintained his roll as an instructor, teaching at the New York School of Fine and Applied Art, at the University of Virginia, Charlottesville, and at the Trenton Academy and the Holmquist School in New Jersey. At the time of his death he held a chair at the Philadelphia School of Design for Women.
Bredin was a member of many clubs and professional organizations including the Philadelphia Art Club, the Salmagundi Club, the National Arts Club, the National Society of Portrait Painters, and the Societ‚ Internationale des Beaux Arts et des Lettres, Paris. From his first appearance in an Academy annual in 1907, Bredin was consistently represented in Academy exhibitions to the year of his death. In addtition to the 1914 Hallgarten prize, he received the Academy's Maynard prize in 1921.