Posters in the window feature an advert for the Rabbit's Foot Minstrels, a once famous traveling show that featured Black talent across the segregated South of the Jim Crow era, most famously through the Mississippi Delta region and beyond. During the 40's a Billboard ad tabbed the program as "the Greatest Colored Show on Earth"and seeking "Comedians, Singers, Dancers, Chorus Girls, Novelty Acts and Musicians." It was owned by various people until its ultimate demise as times and tastes changed in 1959. An historical roadside marker in Port Gibson, MS touts the impact of the Rabbit's Foot troupe on the development of blues music in American culture.

The soldiers are standing at the side of the Farmers Supply Company at 801-803 Noble Street. Some earlier sources give the address as 715 Noble. They sold a plethora of different goods including International trucks, farm and industrial tractors and equipment, buggies, wagons, feed, seed, harnesses, stoves, etc.

Also seen in the photo are the following businesses.

800-802 Noble: The Model Laundry
804-808 Noble: Farmers Supply Co. Used Cars
818-822 Noble: Callahan Grinding & Machine Co., Inc.

The picture below shows the front of the building, which burned down in the 1980s. All of the other structures are now gone as well.

The "nearby Army camp" would have been Camp McClellan (later Fort McClellan, which was closed in 1999).

Why do the light streaks from passing vehicles pass behind the signs and mailbox but in front of the soldiers?

[Because they weren't standing there when the cars went by. - Dave]