Essayons was a dredge boat of the United States Army Corps of Engineers built to clear navigable channels at the mouth of the Mississippi River.

Larger ships using the Port of New Orleans struggled to transit the river's mouth due to a lack of a deepwater channel, and many went aground.

[1] After the Civil War, merchants in New Orleans were eager to ship cotton and other agricultural commodities overseas, but the channel had silted in to a depth of only 14 feet (4.3 m).

On June 23, 1867, Congress appropriated $75,000 "for improving the mouth of the Mississippi"[2] and sent brevet Lieutenant Colonel Miles D. McAlester, Captain of Engineers, to take charge.

After contracting with private dredgers without notable success, McAlester decided that the Corps of Engineers needed its own dredges.

The Army and Congress agreed, and on March 29, 1867 authorized the construction of two dredge boats (but funded only one) to maintain a channel at the mouth of the Mississippi.

He advertised for proposals to build the ship,[4] and the bidding was won by the Atlantic Works in East Boston.

After sea trials, including some dredging in Long Island Sound, Essayons sailed from Boston for New Orleans on June 17, 1868.

These were used to sink the bow down, driving the dredging propeller deeper into the mud on each successive pass of the ship.

[8] There were rudders and pilothouses at both the bow and stern of the ship, so she could be piloted both into a sand bank she was dredging and out of it again as she made multiple passes to widen a channel.

Her dredging method was to approach a sand bar from its seaward, deeper, side using her aft propeller.

Material thrown up by the propeller would wash aft, carried by the river's current, and fall into the deeper water.

The ship was plagued with mechanical troubles in her early days, at one point breaking off all four blades of her dredging propeller.

As many as fifty ships at a time anchored off Southwest Pass waiting for dredging to cut through sandbars.

[12] Shipping traffic declined and while the Corps of Engineers remained loyal to its dredges, frustrated shippers, and Congress began to search for other solutions.

On August 14, 1876 Congress approved spending up to $100,000 to dredge the Southwest Pass until there was a channel 18 feet (5.5 m) deep.