48 Hudson Avenue, also known as the Van Ostrande–Radliff House, is the oldest building in the city of Albany, New York. It was believed by Paul Huey, in the Albany architectural guide of 1993, to have been built in 1759 by Johannes Radliff when he married Elizabeth Singleton because he believed it was built after the stockade was moved south by one block. Research done by Albany historian John Wolcott proved that it had been occupied by Johannes van Ostrande between 1728 and 1734 and that a mortgage Radliff had on the house referred to it as "formerly van Ostrande." The Lamont-Doherty Earth Sciences laboratory of Columbia University performed dendrochronology on a wood core sample from the building to confirm that the building dated from 1728. It has been listed on the National Register o