Born in 1878 on a farm in Westmoreland County, Pennsylvania, Charles Rosen began his career as a photographer. When he was still in his teens he moved to Ohio to join a friend who ran both a photographic studio and an art gallery. The gallery was an eye-opener for Rosen, and by 1900 he moved to New York to study painting.
Rosen attended the school of the National Academy of Design and was also a pupil in the "New York School," conducted by William Merritt Chase and Frank Vincent Dumond. By 1903 he had enough money to marry Mildred Holden and the couple settled in New Hope, Pennsylvania, where they were to stay for the next seventeen years. Rosen became a member of the New Hope School of landscape painters, inspired by the scenery along the Delaware River and the Lehigh Canal. In 1916 Rosen was awarded the National Academy's Inness Gold Medal and the Altman Prize. This was a climactic moment in his career, and he was honored with seven one-man shows. He was also elected to the National Academy.
Charles Rosen first visited Woodstock, New York in 1918 to teach at the summer school of the Art Students League. He found the surroundings congenial and stimulating, and in 1920 he went to live there with his wife and their two daughters. His near neighbors were his old friends George Bellows and Eugene Speicher. In 1922, along with Henry Lee McFee and Andrew Dasburg, he launched the Woodstock School of Painting.
Woodstock was Rosen's home for thirty years. He taught for a time in Columbus, Ohio, and later in San Antonio, Texas. Commissions he was awarded by the Treasury Department Art Project for murals in public buildings took him to Beacon and Poughkeepsie, New York, and to Palm Beach, Florida. However, Woodstock, its neighboring towns, and its surrounding countryside down to the Hudson River gave him the subject matter for half a lifetime's paintings. To many critics, the scenes he painted in the Hudson River towns of Rondout and Saugerties are his most successful. When he died in 1950, Charles Rosen was the acknowledged dean of Woodstock artists.