On July 8th, 1848, the Shrewsbury Inlet closed for the last time, converting Sandy Hook from an island back to a peninsula for good. Over the decades, storms and shifting sands resulted in the inlet closing and reopening several times. When open, it provided a natural channel connecting the Shrewsbury and Navesink Rivers with the Atlantic Ocean. The Inlet was very popular with fishermen and boaters who had easier access to the ocean, not having to navigate all the way around the tip of Sandy Hook, but it made commerce and defense activity on Sandy Hook more of a challenge. In 1847, the steamboat Cricket wrecked on the inlet sand bar, near what is now Plum Island, and sand built up around the wreck, hastening the final closing. Soon after, construction of a railroad and the Sea Bright-Monmouth Beach Sea Wall made the Shrewsbury Inlet closure permanent.
Salter, Edwin. (1874). Old Times in Old Monmouth. Printed at the office of the Monmouth Democrat, 1874, Freehold, N.J., p. 144.
Woolman and Rose. (1878). Historical and Biographical Atlas of the New Jersey Coast, p. 20.