Schlaikjer was born on a boat sailing to New York from Denmark where his parents had been visiting relatives. He grew up on a ranch in South Dakota where he did his first drawings of horses. In his early teens he worked on a Chicago newspaper and then later as a railroad telegraph operator, real estate salesman and as an infantryman during World War I (1917-18).
He attended the Art Insitute of Chicago, the school of fine arts in Lyons, France and studied with Harvey Dunn in New York City. In 1922 he married Gladys de Groot.
During World War II he did posters for the U.S. Government and afterwards maintained studios both in Washington and New York. He had a number of important government portrait commissions.