Tim McGrath

is the author of "Give Me a Fast Ship: The Continental Navy and America's Revolution at Sea"

Once upon a time, Philadelphia was a shipbuilding superpower.

In fact, the city was once the greatest shipbuilding port in the Western Hemisphere. The waterfront was a veritable forest of masts and spars, whose shipyards ran from what is now South Philadelphia north to Kensington. Over three centuries, practically every family had at least one relative who was a sailor, carpenter, rope or sail maker, chandler, or blacksmith. Joshua Humphreys was the Steve Jobs of shipbuilding, his innovative designs admired and imitated the world over.

Ship launchings were the Eagles-Cowboys games or Springsteen stadium concerts of the day. When the frigate United States - sister ship of the Constitution - was launched in 1797, more than 20,000 citizens (in a city of about 30,000) crammed the docks, jammed the nearby streets, and were packed like sardines on the rooftops to watch the massive ship race down tallow-covered ways, hurtling like a titanic roller coaster inches above the heads of convicts stationed alongside the dangerous keel blocks that, seconds earlier, held Commodore John Barry's flagship in place. When the ship splashed into the Delaware, the ensuing wave rocked dozens of smaller craft, filled to their gunwales with curious onlookers. Celebrations went well into the evening.

By the time the Navy moved shipbuilding to League Island in 1871, warships had changed dramatically, and Philadelphia's inventive shipwrights responded wonderfully. Among their successes during the Civil War was the New Ironsides, a three-masted, wooden-hulled ironclad that withstood enemy gunfire much as Old Ironsides did 50 years earlier. For the next century, Philadelphians built and launched many a grand vessel for the Navy, including the battleship New Jersey, which sailed in every conflict from World War II to the Persian Gulf. A Navy Yard job meant both service and security. For generations, such was life in Philadelphia.

All that ended decades ago. The shipyards that gave our Navy frigates, ironclads, and aircraft carriers are long gone, along with Shibe Park, Stetson hats, and Republican mayors.

But wait a minute.

With little fanfare, but a great amount of hard work and creativity, two new warships have been built - if not actually launched - at the Philadelphia waterfront, thanks to the boat builders and volunteers at the Independence Seaport Museum.

The first, the schooner Diligence, is the centerpiece of the museum's current exhibit, "Patriots and Pirates," about the founding of the Navy right here in Philadelphia. The original Diligence, designed by Humphreys, sailed the Caribbean with Barry's first squadron, cruising for French prizes during the Quasi-War from 1798 to 1800.

Well over 4,000 work hours have gone into Diligence's construction. And while "Patriots and Pirates" features an array of artifacts, interactive games, and weaponry displays, it is the rolling deck of Diligence, and her rigging, ship's wheel, and working cannon, that brings out the glee in every youngster and the Walter Mitty in any grown-up.

The second ship also sprung from the inventive minds and seasoned hands of the Seaport Museum's boatbuilders and volunteers: a privateer, to be officially "christened" when her home port, the Museum of the American Revolution, opens in April. Many a privateer was manned by Philadelphians, including the Royal Louis, captained by Barry's friend Stephen Decatur Sr. Among her crew was a free African American teenager, James Forten. When the ship was captured by the British, Forten and his shipmates were confined aboard the prison ship Jersey in the East River, the Andersonville of the Revolutionary War - and that's just the beginning of Forten's remarkable story.

Our waterfront is already blessed to have the Olympia, Commodore George Dewey's flagship from the Spanish-American War that also brought home our Unknown Soldier from France; the Becuna, a World War II submarine that saw action in the Pacific; and the majestic New Jersey, just a ferry ride away. With the Diligence and the "new" privateer, residents and tourists alike can take a terrific walking tour of the American Navy. Board any of them, and one feels the emotional impact of the victories and sacrifices made by generations of sailors and Marines since 1775.

President Harry S. Truman once said, "The only thing new in the world is the history you do not know." When presented accurately and passionately, as these museums do and will do, history not only teaches us about the past, but serves to encourage, scold, and at times warn us of what squalls await if we don't pay attention.

Any sailor can tell you that.