My WPA Mississippi book lists the house known as ‘Merrehope‘ in Meridian as the J.H. Gary House. It’s at 905 31st Avenue.
The historical marker says:
A 20-room Neoclassical Revival mansion completed in 1904, the house began as a small cottage which served as headquarters for Confederate Gen. Joseph E. Johnston in 1863. Merrehope is now a museum of local history.
My WPA book says that “the single-story ell, which extends to the rear, was the headquarters of Gen. Leonidas Polk, Commander of the Confederate troops stationed in Meridian.”