Career
He was of the Democratic Party. He became the "Dean" of Chicago delegates and played a role in the early career of Dan Rostenkowski. O"Brien died in office of a stroke on April 14, 1964.
The T.J. O’Brien Lock and Dam approximately 7 miles from Lake Michigan on the Calumet River in Chicago at the head of the Illinois Waterway is named after Congressman O’Brien.
