I found this on the USC Archive; the caption said that it shows Crenshaw looking south, with a car crossing it at 48th Street, 1930-1939.
WRONG.
I saw the lamp posts and immediately knew that this shows Olympic Boulevard, being that those lamp posts are the "Olympic Specials." It's nice to see them here with their original teardrop luminaires. So, this is actually looking west along Olympic Boulevard at Crenshaw. You can even see the tower of Los Angeles High School to the left. This is where residential 10th Street branches off, though today, 10th Street no longer directly intersects with Olympic and Crenshaw. 10th Street is now closed at S. Victoria Avenue, and a landscaped grassy triangle has been created on that corner, with a driveway to a Rite Aid.
Vons Supermarket apparently was celebrating its 33rd anniversary in this picture, so that would date it to 1939.