Rasmussen was born in Germany and died in Shillington, Pennsylvania. Along with Charles Hofmann and Louis Mader, he was one of the three "Pennsylvania Almshouse Painters," so named because they were committed to the Berks County Almshouse outside of Reading, Pennsylvania. Rasmussen immigrated in 1865, entered the poorhouse in 1879, and imitated Hofmann's style, as did Mader. A major Almshouse exhibition was held at the Abby Aldrich Rockefeller Folk Art Museum in Williamsburg, Virginia in 1968.