In 1880, most of the southern side of 19th Street between Sixth & Fifth was still taken up by empty lots. 290 seems to be the only building indicated on the Bromley map of that year that is still standing today. By 1886, this side of the block was starting to fill in. One of the houses making its appearance on the 1886 Robinson's map is no. 270, set right at the back of its lot. It's still here on the block, though there's not much left externally to indicate its age.
270's been on the market for over a year at $1,450,000, with most ads. claiming it was built in 2015, but a couple dating it at 1907 or 1910.. It's been listed as a "preconstruction building" or "house being sold for property value." neither of which sound particularly cheerful. Recent applications for new construction on the lot were disapproved. It's now listed as being in contract.