Few Americans pay much attention to Patriots' Day, but they should

"Hardly a man is now alive / Who remembers that famous day and year," wrote the poet Henry Wadsworth Longfellow about April 18-19, 1775. Of course, Longfellow in 1863 wrote his once-popular poem "Paul Revere's Ride" in order that future generations would never forget the events of that night and day. But no one reads Longfellow anymore.

It is not surprising, therefore, that the meaning of April 19, 1775, has faded from our memory. Outside of Massachusetts, which celebrates the day by hosting the Boston Marathon but moves it to the nearest Monday, few Americans pay much attention to Patriots' Day. This is too bad. For on that day 242 years ago, the battles of Lexington and Concord set in motion an eight-year-long war with Great Britain that resulted in the birth of the United States of America. Consequently, all Americans have an immense stake in Patriots' Day and in the American Revolution that it initiated.

This is why the new Museum of the American Revolution located just off Independence Mall in Philadelphia has scheduled its official opening for April 19. It will become a site that will remind Americans, as no other museum can, why they are the "one People" promised in the opening lines of the Declaration of Independence.

Every nation has sites of memory that give its citizens a sense of themselves as a single people. But we Americans have a special need for these sites of memory. A country like ours, composed of so many immigrants and so many races, religions and ethnicities, has never been able to take its nationhood for granted.

In America, said John Adams, even at the outset of the country's history, there was nothing like "the Patria of the Romans, the Fatherland of the Dutch, or the Patrie of the French." Adams was appalled by the extraordinary diversity of religious denominations and ethnicities in America. In 1813, he counted 19 different religious sects in the country. "We are such an Hotch potch of people," he concluded, "such an omnium gatherum of English, Irish, German, Dutch, Sweedes, French &c. that it is difficult to give a name to the Country, characteristic of the people."

No wonder then that at the end of the Declaration of Independence the members of the Continental Congress could only "mutually pledge to each other our Lives, our Fortunes, and our sacred Honor." There was nothing else but themselves that they could dedicate themselves to — no patria, no fatherland, no nation as yet.

In comparison with the nearly 2½-centuries-old United States, many countries in the world today are new, some of them created in the relatively recent past. Yet many of these states, new as they may be, are undergirded by peoples who had a pre-existing sense of their ethnicity, their tribal and blood connections, by which they meant their nationhood. In the case of the U.S., the process was reversed: We Americans, were a state before we were a nation, that is, a people with a natural sense of oneness.

Of course, in the present this peculiarity of American nationhood, this lack of a common ethnicity, may be our saving grace. It may turn out to be an advantage in the 21st century, dominated as it is by mass immigration from the south to the north and east to west. It certainly enables the U.S. to be more capable than other countries of accepting and absorbing immigrants. Of course, America has its own recent problem with immigrants, but these problems pale in comparison with the problems of immigration the European nations are facing and will continue to face over the rest of the century.

Because we are not a traditional nation and have no ethnic base, the American Revolution has become the most important event in American history. It is what holds us together and makes us a nation. Not only did the Revolution legally create the United States, but it infused into our culture our noblest ideals and highest aspirations — nearly everything that we cherish: our beliefs in liberty, equality, democracy, and the well-being of ordinary people.

On the eve of the Civil War, Abraham Lincoln came to realize how important the Revolution was in defining the nationhood of the United States. It was the adhesive for a diverse people. Half the American people, he said in 1858, had no direct blood connection to the founders of the nation. These German, Irish, French and Scandinavian citizens had either come from Europe themselves or their ancestors had, and "finding themselves our equals in all things," had settled in America.

Although these diverse ethnicities may have had no authentic connection in blood with the revolutionary generation that could make them feel a part of the rest of the nation, they had, said Lincoln, "that old Declaration of Independence," with its expression of the moral principles of liberty and equality, to draw upon.

These moral principles, which were, said Lincoln, "applicable to all men and all times," made all these different peoples one with the founders, "as though they were blood of the blood and flesh of the flesh of the men who wrote that Declaration." With this extraordinary image Lincoln linked all Americans, no matter how recently they had come to the U.S., to the events of the American Revolution.