“Ferguson went to third on a grass-rubber to right field, and cleared the bases.” “Baseball: Grand Match at Cedar Hill: Louisville vs. Brooklyn,” Louisville Courier-Journal, July 3, 1868, p4
Previous earliest use (Dickson Baseball Dictionary, 3rd edition, 2009):
1870. “Swandell’s hit to centre field cleared the bases.” (Putnam’s Magazine, March; Richard Hershberger).