Charles Rosen was born on a farm in Reagantown, Pennsylvania in Westmoreland County. As a young man he was interested in photography and opened his own studio in the Pennsylvania coal mining town of West Newtown when he was sixteen years old. His love of photography eventually brought him to Ohio, where his interests shifted to newspaper illustration. In pursuit of this new dream, Rosen moved to New York and enrolled himself in classes at the National Academy of Design, where he studied with Francis Coates Jones. He then enrolled at the New York School of Art, where he studied with Frank Vincent Dumond and William Merritt Chase. It was at the New York School of Art that Rosen decided to dedicate himself to landscape painting.
In 1903 Rosen married, Mildred Holden, and he and his new bride moved to New Hope, Pennsylvania. While in New Hope, Rosen developed relationships with fellow painters, Daniel Garber, Edward Redfield and William Lathrop. Rosen quickly developed a personal style. He became well known for his large landscapes, especially his snow scenes. Unlike his contemporary Redfield, who painted large canvases in a day, Rosen took time composing his pieces, working both outdoors on site and also in the studio.
In 1918, Rosen began teaching at the Art Students League summer school in Woodstock, New York. Two years later he would move to Woodstock and remain there for the rest of his life. He died in 1950.
Rosen was an associate member of the National Academy of Design. He was also a lifetime member of the Salmagundi and National Arts Clubs. He won two Hallgarten Prizes from the National Academy of Design for his landscapes. In 1915, he was awarded a silver medal at the Panama-Pacific International Exposition.