Company Names, addresses, dates:
  Hires Root Beer, 9002 50th Ave, College Park MD (1957-1958) ^1,2
  Hires Root Beer, 9002 50th Ave, Branchville MD (1958-1961) ^2,3

Notes:
Wikipedia says that Hires Root Beer was introduced in 1876, and was manufactured by Dr Pepper

The Hires Root Beer bottling company of Washington DC was actually located in Maryland, not D.C., so I was almost didn't create this web page.

In 1958, the newspaper mentions of the Hires Bottling company changed the city name from "College Park" to "Branchville". Branchville was a section of College Park. ²
In 1961, there was a newspaper announcement that the Rock Creek Ginger Ale Co was taking over as sole manufacturer and distributor of Hires Root Beer in the Washington DC area. ³

One of the bottle caps below says "TV COLA" on the front. I've also seen bottle caps from Hires Washington DC that say:
  TV / ORANGE / SODA
  TV / IMITATION / GRAPE / SODA
I think that "TV" is short for "True Value", as I have seen some soda cans that said "TV True Value Brand", but I don't know for sure. I haven't found any information about "TV" associated with "Hires", other than the bottle caps.

	This is a brown bottle cap with orange and white letters that say:   (front): Hires / ROOT BEER / CARAMEL COLORED / ...   (edge): BOTTLE BY HIRES BOTTG CO WASH, D.C.
	This is a cream-colored bottle cap with blue and brown letters that say:   (front): DIET / Hires / ROOT BEER / FALOVORED / ...   (edge): BOTTLED BY HIRES BOT CO WASH DC
	This is a yellow bottle cap with red letters that say:   (front): KICKAPOO / JOY JUICE   (edge): BY HIRES BOTTLING CO OF WASH DC
	This is a black bottle cap with white letters that say:   (front): TV / COLA   (edge): HIRES BOT CO WASH D.C.