Backstop (Screen) (1868)

“Crane and Mills get home on ball over back-stop.” Buffalo Commercial Advertiser, June 17, 1868, p3

Previous earliest use (Dickson Baseball Dictionary, 3rd edition, 2009):
1870. “The [Washington] Olympic Club…[has] a fine club house, plenty of seats and a fine pagoda over the back stop.” New York Clipper, February 19, 1870. [Darryl Brock]