This week started on Monday, February 21, with a national holiday across America, a day set aside not only to celebrate the February birthdays of Presidents George Washington and Abraham Lincoln, but also to honor all past presidents of the United States.


In 1971, then-President Richard Nixon signed a federal law that proclaimed the third Monday in February a national holiday called Presidents Day. The law ended the longstanding American custom of celebrating two national holidays in February to honor the birthdays of Abraham Lincoln on Feb.12 and of George Washington on Feb. 22. Some critics of the combined holiday believe Presidents Day -- in honoring all past U.S. presidents, detracts from the unique contributions made to the nation by Washington and Lincoln.


Seth Fein, an American History professor at Yale University, says most Americans consider the two men to have been the nation's greatest presidents. "George Washington, obviously, is the general who headed the Continental Army and the first president of the United States, and in many ways, [he was] the personification of the United States in the beginning of its political history as an independent state," he said. Lincoln is so deeply revered "for being president during the Civil War [1861-1865] ... putting the country back together."


Without George Washington, there may not have been a United States of America. "He was a figure that was so respected that he helped launch a nation when people from different parts of the country remained still very suspicious of each other," says University of Virginia American History Professor Michael Holt. "In fact, there was concern about warfare breaking out among differing states. But everybody agreed that he was the one person that all could agree on as the first he was, I think, indispensable."


Professor Holt praises Washington as a forceful leader who established important precedents in the relationship between the President and Congress ? for example, when his administration was negotiating a treaty with several American Indian tribes.


"The wording of the Constitution gives the president authority to conduct foreign policy with 'advice and consent' of the Senate," he said. "Washington comes to the Senate to seek their advice about the terms of the treaty. The Senators get all flustered and say they have to debate this to arrive at a consensus to give you advice. Washington just turned around and walked out. And from then on, foreign policy has been conducted with the 'consent' in terms of ratification of treaties ... but no direct advice [from the Senate] going into making them."


Like George Washington, Abraham Lincoln is perceived as a leader who guided the nation through a critical and dangerous transition. Without Lincoln, the nation might not have survived its Civil War. "Some people say he was an intuitive military strategist," said Michael Holt. "He had an ability to explain the meaning of the war to the northern public in memorable terms."


That is something he did so eloquently in a brief and famous address honoring the soldiers killed in a battle at Gettysburg, Pennsylvania, in 1863. "There's that wonderful prose," Professor Holt points out, "about what we say here will little be remembered but what they did here will always be remembered ... and that the purpose of the war was that the government of the people, by the people and for the people shall not perish from the face of the earth."


Abraham Lincoln is also remembered for his Emancipation Proclamation of 1863, which freed the slaves in the rebellious southern states. Mr. Lincoln's commitment to end slavery was also a theme of his second inaugural address in 1865, as historian Holt recalls. "If we must shed a drop of blood for every drop of blood squeezed from the slaves over 200 years, we'll do it in order to prevail in this contest...It's really that message where he makes it clear that ending slavery is as important a commitment as unifying the nation."


Americans have also come to know the personal sides of Presidents Lincoln and Washington, and they know that neither man was perfect. George Washington, for instance, was a slave owner.  But historian Seth Fein believes that, when Americans reflect on their past presidents, they usually look beyond their flaws. "The fact that many people can identify with George Washington, Presidents Day, the United States despite knowing those things," he says, "might speak to the need for political symbols, for national identity, and for heroes."


On Presidents Day, Americans honor those heroes who've held the nation's highest office over the past two centuries.