A History of Short Words

From the New York Times Crossword Puzzle

ABA

Sun, 9 Jan '22
Attorney's org.
Tue, 14 Dec '21
Lawyers' group, for short
Tue, 6 Apr '21
Defense org.?
Sun, 21 Mar '21
Org. to which Taft was elected president after serving as U.S. president
Mon, 25 Jan '21
Lawyers' org.