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
Assassination of Abraham Lincoln
Assassination of Abraham Lincoln
John Y. Culyer