He then spent one year in an architect's office in New York city. He was a member of the engineer corps under Frederick Law Olmsted, superintendent of Central Park, New York city, where he developed a talent for landscape architecture, especially in road construction, surface treatment and planting. In 1861 he accompanied Mr. Olmsted to Washington, D.C., where he assisted in organizing the U.S. Sanitary Commission. He then entered the engineer corps, U.S. army, under General George Dashiell Bayard, and was engaged on fortification and defence works in Virginia south of the Potomac river. On April 14, 1865 Culyer witnessed the Assassination of Abraham Lincoln at Ford's Theatre in Washington, D.C.