Conversation so far:
What did McGinnity do later in life?
McGinnity purchased the Newark Indians of the Class-A Eastern League (EL) for $50,000 ($1,361,852 in current dollar terms) in 1909 from Frank J.
Farrell.
Did the team do well?
That season, he had a 29-16 record.
Did he own the team the rest of his life?
McGinnity sold the Tigers and purchased the Butte Miners of the Northwestern League in 1916.
How did the Butte Miners do?
CANNOTANSWER.
How much did he buy the Butte Miners for?
CANNOTANSWER.
Are there any other interesting aspects about this article?
McGinnity served as player-manager of the Danville Veterans of the Class-B Illinois-Indiana-Iowa League in the 1922 season.
Was that team successful?
McGinnity won 15 games at age 52.
One of those wins was a shutout, pitched in a record one hour and seven minutes.
Did he do anything else in his later career?
He pitched in his final professional game on July 28, 1925, after participating in an old-timers game earlier in the day.

Question: What did he do after playing professionally?
Self-contained rewrite: What did Joe McGinnity  do after playing professionally?