Harvard Summer School was created in 1871.
Harvard Law School was created in 1817.
Harvard-Westlake School was created in 1900.
Harvard Business School was created in 1908.
Harvard Extension School was created in 1910.
Harvard Engineering School was created in 1918.
Harvard Divinity School was created in 1816.
Harvard Medical School was created in 1782.
Harvard School of Public Health was created in 1922.
Harvard Graduate School of Education was created in 1920.
Harvard Graduate School of Design was created in 1936.
Harvard School of Dental Medicine was created in 1867.
No, Harvard University is a college, however I believe they do have a summer progam for high schoolers