We're guessing this Cornerspotter wasn't too hard as all of our commenters were able to figure out that this early 20th century photo was of the U.S. Government Printing Office (GPO). The corner, itself, that is shown was under some debate, but the photo shows the building at the corner of North Capitol and G Streets. The GPO agency was founded in 1861 and is a part of the legislative branch. In charge of printing documents produced by and for the federal government, the agency has been at the forefront of technological change and was the world's largest printing concern for most of its history. The GPO now has a history program titled, "Keeping America Informed," meant to educate the public on the agency's more than 150 years of history.
· Giant Government Printing Office Building in 1909 [Ghosts of DC]
· The History of the Government Printing Office [U.S. Government Printing Office]
· Hint: This Site is Dedicated to Keeping America Informed [Curbed DC]
· Cornerspotter archives [Curbed DC]