The Alexandria Fire Department traces its roots back to 1774 when George Washington helped found the fire department as the privately funded Friendship Firehouse Company. The original building on S. Alfred Street has a fascinating backstory (also here is a Library of Congress reference on the building itself [PDF]).
As the Friendship Firehouse Museum webpage says:
In a town of mostly wooden buildings, where open flames provided heat, light and cooking on a daily basis, fire was a constant danger. The Friendship, Sun, Relief, Hydraulion and other local volunteer fire companies served the community faithfully, particularly during enormous blazes in 1827, 1855, 1871, and 1922. Some of their stories and equipment are preserved today in the Friendship Firehouse Museum.
Firefighters have long been honored in parades in Alexandria. Just a few short weeks ago, I published an article about a 1910 firefighter convention postcard. From personal experience, I can tell you that firefighters are still revered in Alexandria's three major parades.
Pictured here is a 1909 parade on King Street featuring a hook and ladder. It looks pretty different than the modern hook and ladder shown below this article.
Looking closer at the photo, it appears to be taken from the second floor of 500 King St., looking across King Street and Pitt Street at the south side of the 400 block of King Street at Marshall House just at the end of the block around 435 King.
Comparing the hook and ladders
The postcard reads: "You just ought to have seen Clydes "Eyes" GW. It is addressed to Mr. S.S. Sloan, 111 E. Broad St., Richmond, VA
That's the address of the former Buchanan and Son diamond jewelers in Richmond, VA. It has seen better days. I'm not sure if there were apartments upstairs.