The seaport town of Portsmouth became important in the shipbuilding industry. Several businesses grew up in the area. The Meserve Shipyard was bought out by George Raynes. By 1850 Raynes had built 32 three-masted ships and 10 clipper ships. Other Portsmouth shipyards were the Tobey-Little, Pettigrew, and the Hanscom Shipyard.

At the time of the Revolutionary War, the licensing of private vessels became more common in every seaport along the Atlantic coast. Privateering became about the most destructive type of naval policy the Continental Congress would support. Privateers had been seizing merchant ships for generations, selling their cargo, and distributing money among the crew. However, America didn't have time to build many of its own ships, and privateering became a legal means of obtaining merchandise and ships in time of war.

One of the most famous privateers from New Hampshire was John Paul Jones. John Paul Jones lost no time in getting a naval post. On December 7, 1775 he was made first lieutenant in the Continental Navy, and was assigned to the Alfred, his largest ship.

The Continental Congress voted to have 13 frigates built for wartime use. John Langdon, a wealthy merchant and politician managed to have three ships built in Portsmouth, NH : the Raleigh, the Ranger and the America.. In 1776 the Raleigh became the first of three U.S. Navy warships to be built. The New Hampshire seal, on the state flag displays the Raleigh on it.

In 1777, the Ranger was built at Portsmouth, intended for John Paul Jones. First named Hampshire for its port of origin, the ship was contracted among the first fleet of the new American navy. Wealthy builder John Langdon fashioned it after his privateer vessel "Portsmouth".The Ranger was the first to fly the American made flag, on July 2, 1777.

John Langdon planned for the Ranger to be commanded by his friend John Roche, but his career made him unacceptable to the navy. John Langdon then suggested the already popular John Paul Jones. Jones' orders were to pursue British merchant ships, but not to sink them. Hostilities had begun and there was not enough time to build ships. America needed every ship they could get, and "by the capture of good merchant ships, we might assemble a good working navy in a short time." a decision he later regretted as the two men remained at odds for years to come.

The America was the third of the first three U.S. Navy ships built in Portsmouth. By the time the America was completed, the war was all over, and Congress sold the ship to France. Portsmouth stopped making the wooden ships and eventually became known as the Portsmouth Naval Ship Yard. Between 1939 and 1945, 85 submarines were constructed at the shipyard. Now this shipyard is used to repair nuclear submarines.

This is the home of sea captain George Purcell. John Paul Jones was one of the boarders at the house in 1777, while waiting for his warship, the Ranger , to be outfitted. He returned again in 1781, to await the building of the America..

The message on the signpost reads: John Langdon, merchant and statesman, was born June 26, 1741, on this farm which was first settled by the Langdon family about 1650. With his brother Woodbury, he became a successful trader and shipbuilder. During the American Revolution, he supervised construction of the Continental warships Raleigh, Ranger, and America at his Portsmouth shipyard, was in active military service, and personally financed General John Stark's expedition against Burgoyne in 1777.