When he and attorney Clarence Miles purchased the Orioles in 1953, Hoffberger was the largest single shareholder in the Orioles, but was initially a silent partner with Miles (1954–1955), James Keelty (1955–1960) and Joe Iglehart (1960–1965). During this time, however, he bought more and more stock until he acquired controlling interest in 1965. He immediately brought in Frank Cashen, National's advertising director, as executive vice president. Under the direction of Cashen and general manager Harry Dalton, the Orioles won four AL pennants and two World Series from 1966-71. He was a 1996 honoree into the Orioles Hall of Fame, inducted with Cal Ripken, Sr. and Billy Hunter. 400 showed up at the luncheon at the Sheraton Inner Harbor Hotel.

This 8x10 photo has been signed in blue by Hoffberger. It shows Frank Robinson pouring champagne on Hoffberger's head in celebration.