At the same time, a two-story parking garage was added adjacent to the hotel, designed by Gustav Heye.

The insurance company United Services Automobile Association was formed based on a meeting of twenty five United States Army Officers on June 20, 1922 at the Gunter Hotel to discuss the procurement of reliable and economical auto insurance.

[6] At this site, General David E. Twiggs surrendered $1,600,000 in federal property to the forces of Confederate Texas.

The Gunter Hotel was also the site of the headquarters of Brevet Colonel Robert E. Lee who assumed command of the Post of San Antonio on August 5, 1857.

On November 27, 1936, Room 414 of the Gunter was the scene of a historic recording session by blues artist Robert Johnson.