Manhattan Davis began his career in property speculation in New York with financial backing from the banking house of J.L. & S. Joseph & Co. The Joseph were a major firm of securities brokers and had the agency for the Rothschilds but became overextended and was a casualty of the crash of 1837. In 1831, Davis built
Federal style townhouses in red brick on both sides of East 8th Street, between Third & Second Avenues, developing the entire block known as
St. Mark's Place. The townhouses originally stood "virtually alone in the meadows and marshland of the
Stuyvesant family's farm", heightening "the grandeur of these two rows". There remain three surviving townhouses from this development: the
Hamilton-Holly House at 4 St. Mark's Place, the building at 25 St. Mark's Place, and the best preserved of the three, the
Daniel LeRoy House at 20 St. Mark's Place. Further developments by Davis in the area include Carroll Place, on the block from Thompson Place to LaGuardia Place. Toward the end of the recession that followed the
Panic of 1837, which lasted until the mid-1840s, Davis was able to purchase 400 plots on Fifth Avenue (north of Twentieth Street) for a few hundred dollars each and built a complete block of fine dwellings between East 31st and East 32nd Street.
Staten Island Between 1834 and 1835, Davis bought land on
Staten Island that ran from the quarantine station to Sailors' Snug Harbor, or nearly the whole of northern Staten Island. He called the area New Brighton (after a coastal resort in England), and built Greek revival style houses on the shoreline. An association of wealthy entrepreneurs was set up to further develop the land and promote the area as a suburb, with easy access to New York via steam ferries. However, almost immediately, the financial crisis known as the
Panic of 1837 resulted in foreclosure of the association. Davis, with co-partners, re-acquired the development and managed to ride out the recession. Davis lost a substantial amount of money during this period but survived the crash, while the bankers who had initially provided support for Davis, J.L. & S. Joseph, failed.
Minnesota Davis and two of his sons-in-law, Frederick C. Gebhard and
John F. A. Sanford, became involved with financing the
St. Anthony Falls Water Power Company in Minneapolis. Sanford, who had been a frontiersman, was acquainted with the men developing the project and they invited him to invest. He in turn brought in Davis and Gebhard. The relationship between the developers and the New York backers was not good, and finally broke down following the death of Sanford in 1857. Gebhard died in 1865, his brother William H. Gebhard became involved, court action followed, and it took several years for the situation to be finally resolved.
Later life Davis became extremely wealthy, and was considered the greatest real estate speculator of his time. Among New York City real estate owners, , Davis's holdings were placed third after
John Jacob Astor and
department store mogul
Alexander Turney Stewart. In the mid 1860s, Davis moved with his family to Italy. ==Personal life==