East 70th Street and four on East 71st, a concept of rare civility in New York which dates to 1928. 41 East 70th Street was built for Walter N. and Carola Warburg-Rothschild. 45 East 70th Street was built for Arthur S. and Adele Lehman, the son of one of the founders of Lehman Brothers. Across from her parents, at 46 Eas