The long-exposure blurred figures and the emulsion degradation give this amazing image an intensely other-dimensional ghostly aura.

Can anyone hear Tubular Bells? (played over the opening scenes of The Exorcist)

The street shown is Grant Place N.W., it still exists, and the street remains one block long as it was in 1901. The street name is often abbreviated on current maps as "G Pl NW" thus making it difficult to find. It is located in the middle of the 700 block between 9th and 10th Streets N.W.

What we are looking at appears to be the corner of 10th Street N.W. and Grant Place N.W. looking down the block towards 9th Street N.W. I believe the front right of the photo shows the rear of the First Congregational Church. The alleyway entrance behind the church is clearly visible followed by the row houses that are shown on Plate 30, Volume 1, of Baist's Real Estate Atlas of Surveys of Washington, District of Columbia published in 1903. The location is two blocks away from Ford's Theatre.

I think the sign identified as "(520? 521?)" actually states "$500 Reward," followed by some unreadable text. The buildings on this street would have been numbered between 900 and 999.

Everything on the block appears to have been demolished. Interestingly, though the original First Congregational Church, completed in 1868, is also gone, the congregation is still there. The original church was eventually declared unsafe in the 1950s, it was torn down, and a new facility was eventually built (completed 1961). The church's website states that the church acted as a staging area for the 1963 March on Washington. This second building has now been torn down, and it was replaced by a third building in 2012 that is far larger than the original church ever was. Like the original church, the current church entrance remains on G Street N.E.

There is a Grant Place N.E., but it is located on the other side of the Anacostia River, and the details, like the alleyway, do not appear to fit this location.