The photo above, from the NYPL digital archive, shows South William Street (AKA a block from our office) in the mid-1860s. We’re looking at, from left to right 9, 11, 13, 15, and 17 South William. Here’s a roughly similar view in 2014 (not current because there is now scaffolding in front of 9 and 11):
First, how do I know the photo is the mid-1860s? The businesses that are visible all have move-in and move-out dates. For example, I found a notice in the Trow City Directory of 1866 that the firm of Brien & Carrere had dissolved. Piecing together that kind of evidence is slow, but fortunately I found a description of this photo from the Bulletin of the New York Public Library: “Swift [the photographer] at this address [in the lower left] in directory 1865/6 and 1866/7; Brien & Carrere only in 1866/7.” If this mattered, as opposed to being a blog post, I’d check the directories myself to confirm. This isn’t absolute proof, but it’s as good as it’s likely to get.
Second, note the big piers in the storefront portions of the facades. Those are solid chunks of granite, used for piers like this in storefronts until they were driven out by cheaper and lighter cast-iron columns in the 1840s and 50s. There are still a number of building in lower Manhattan – mostly on or near South, Front, and Pearl Streets – with piers like that, although most were demolished long ago. Look at the modern photo: the building on the right with “Bavaria” is 19 South William, which is not in the old photo, and it has the same facade, more or less. I’m fairly sure that 13, 15, and 17 South William, which do not look the same, are the old buildings with new front facades put on in the late 1800s or early 1900s to modernize them. If they were new buildings, they’d be bigger, since this is expensive real estate in the Financial District. But putting on a new facade is a relatively cheap way to make an 1820s or 30s loft building look new. Or newer. And finally 9-11 South William is a bigger building built later, so it is a replacement.
Or, I can cheat and look at the Landmarks Preservation Commission designation report for the Stone Street Historic District, which contains these buildings. 9 is a new building constructed in 1929; 11 was completed in 1836 and modified in 1924; 13 was completed in 1839 and modified in 1903; 15 was completed in 1839 and modified in 1909; 15 was completed in 1839 and modified in 1906; and 19 was completed in 1839.