A bar with islands in the Hudson River, on which vessels often ran aground in the old time: mentioned by Carroll (1776), and Morse (1796). N.E.D.

1

1788.  Those stones should be carried to the Overslaugh, or wherever, in its vicinity, the [Hudson] river is filling up.—American Museum, iii. 513/2.

2

1831.  They approached the Overslaugh, a place infamous in all past time for its narrow crooked channel, and the sandbanks with which it is infested.—J. K. Paulding, ‘The Dutchman’s Fireside,’ ii. 5.

3

1835.  The Overslaugh. The Albany Argus says that the obstructions in the Hudson River are to be removed at last.—Vermont Free Press, Jan. 31.

4

1838.  She draws but 30 inches water, and therefore is never detained at the Overslaugh.—The Jeffersonian, May 5, p. 96.

5

1838.  There is a point some distance up the Hudson River known as the Overslaugh or Overslow, but sometimes called “Marcy’s Farm” for the sake of brevity and euphony…. The obstructions at the Overslaugh produce great loss and inconvenience.—Mr. Sibley in the House of Repr., id., Sept. 1.

6

1877.  

        To visit Albany or Troy
  Was quite an enterprise;
In Tappan Zee the wind was flawy,
  And billows oft would rise;
An’d then the overslaugh alone
  For weeks detained a few;
Steamboats and railroads were unknown,
  When this old house was new.
N.Y. Post, March (Bartlett).    

7