Company Names, addresses, dates^1,2,3:
  G. Steuernagel [brewer], 41 1/2 King Street, Alexandria VA (1865-1868)
  G. Steuernagel [restaurant], 31 Prince Street, Alexandria VA (1871-1875)
  G. Steuernagel [restaurant], 30 N. Royal Street, Alexandria VA (1876-1881)
  G. Steuernagel [restaurant], 28 & 30 N. Royal Street, Alexandria VA (1882-1883)
  G. Steuernagel [wine & liquor], 300 King Street, Alexandria VA (1888)

Notes:
George Steuernagel (1828-1889)⁴ was a brewer & restaurant owner. In the book American Breweries III, Steuernagel is listed as an Alexandria VA brewer from 1865-1868². His brewery was at 41 1/2 King Street, which from the 1885 Sanborn map of Alexandria, appears to be roughly where modern day 217 King Street is.
Sometime after he stopped brewing beer, he ran a restaurant at various locations. Many of the advertisements for his restauarants made mention of his selection of wines, liquors, and beers. The dates for his restauarants listed in the section above are the only years I could find in city directory entries or newspaper mentions - so they may not be complete.
The December 15, 1875 Alexandria Gazette makes a brief mention of George Steuernagle being on bail, charged with assaulting and beating 2 men with a club. I couldn't find any further information on the incident.

Bottles:

book # 148 (in the Stoneware section) This is a 7" tall stoneware blob-top bottle with a name impressed in the shoulder: imprinted on shoulder: G STENERNAGEL The 'G' is feint and might just be a smudge or defect. A common spelling error is to mistake a 'u' for an 'n' when you're reading a hand written name, which I beleive is why it has an "N" where a "U" should be. The seller of this bottle said it was dug at a construction site on Braddock Road in Alexandria. war".