We dug up this undated photo at the Library of Congress. It appears to be from the late 1930s or early 1940s. The good news, is that the firehouse is still there. Check out the Google Street View below.
Then and Now: M Street Firehouse
– click image for more –[googlemaps https://maps.google.com/maps?gl=us&ie=UTF8&ll=38.905653,-77.014117&spn=0.005903,0.010965&t=m&z=17&layer=c&cbll=38.905651,-77.014308&panoid=628-4Svj42_RFNJyKokXgQ&cbp=12,6.58,,0,-6.84&source=embed&output=svembed]