Bases Loaded (1871)

“….the barefaced obstruction of a baserunner by McBride, who seemed to be confident that the umpire would allow him to get away with it, closed up the inning, which, at the rate the Athletics were muffing, promised several more runs, especially as the bases were loaded at the time.” Chicago Tribune, June 19, 1871, p4

Previous earliest use (Dickson Baseball Dictionary, 3rd edition, 2009):
1880. “Surely the man who hits safely when men are on base…is of far more value to his club than the man who earns a base for himself twice as often, and makes a weak hit or fouls or strikes out when the bases are loaded” (Chicago Tribune, July 11; Peter Morris).