As anyone who saw a campaign poster in 2008 could surely tell you, Barack Obama is all about change. Change in the White House, most profoundly in the simple, yet stunning, fact that we now have our first black president. Change in the tenor of politics, in an effort to step back from the ferocious partisanship of the past decade. And change in the direction of the country, in the form of a dramatic shift in the priorities and policies of the government.

Yet change, Obama also knows, can be frightening. Too much change can seem radical, threatening, dangerous. During the campaign, Obama had to overcome the deep-seated fears of many Americans that his particular brand of change would only mean change for the worse.

So Obama has always made a conscious effort to balance his calls for change with equal references to the timeless continuities of American history, seeking to cast his own political movement as nothing more than the culmination of the work of Lincoln, Roosevelt, Jefferson, Kennedy, and the other great leaders of our past. (Obama deliberately began his campaign, for example, in the same place that Lincoln began his own run for the White House, and ended it by taking the oath of office on Lincoln’s bible.)

Obama’s best speeches have all been peppered with historical allusions and quotations. Over the course of the campaign, Obama breathed fresh life into some of the most moving phrases offered in the past by Lincoln ("a new birth of freedom"), Martin Luther King ("the fierce urgency of now"), and Cesar Chavez ("yes we can").

This morning’s inaugural was no exception to Obama’s tradition of using the past to frame the present, as the inaugural address was full of historical allusions—some obvious, some not so obvious.

So what exactly was Obama referring to with each of his invocations of the past? Let Shmoop be your guide… Forty-four Americans have now taken the presidential oath. The words have been spoken during rising tides of prosperity and the still waters of peace. Yet, every so often the oath is taken amidst gathering clouds and raging storms. At these moments, America has carried on not simply because of the skill or vision of those in high office, but because We the People have remained faithful to the ideals of our forbearers, and true to our founding documents.

Actually, only 43 presidents have taken the oath. (Grover Cleveland, who won the presidency in 1884, lost it in 1888, and won it back again in 1892, counts as both President #22 and President #24… so while there have been 44 distinct presidencies, there have only been 43 different presidents.) Aside from that bit of random trivia, the new president’s point here is to emphasize the continuity of the presidential transfer of power, in times good and bad, as prescribed in the Constitution (that’s what Obama’s invoking in his references to "We The People" and "our founding documents").

Our journey has never been one of short-cuts or settling for less. It has not been the path for the faint-hearted—for those who prefer leisure over work, or seek only the pleasures of riches and fame. Rather, it has been the risk-takers, the doers, the makers of things—some celebrated but more often men and women obscure in their labor, who have carried us up the long, rugged path towards prosperity and freedom.

For us, they packed up their few worldly possessions and traveled across oceans in search of a new life.

For us, they toiled in sweatshops and settled the West; endured the lash of the whip and plowed the hard earth. For us, they fought and died, in places like Concord and Gettysburg; Normandy and Khe Sahn.

Time and again these men and women struggled and sacrificed and worked till their hands were raw so that we might live a better life. They saw America as bigger than the sum of our individual ambitions; greater than all the differences of birth or wealth or faction.

Here Obama invokes the experiences of a wide variety of Americans, from all walks of life, in triumphing over adversity. Those who "packed up their few worldly possessions and traveled across oceans in search of a new life" would include both the first European settlers of America—the rugged colonists of Jamestown and the Puritan refugees of Plymouth Rock—but also the later generations of immigrants who poured into the country through most of the 19th and 20th centuries. Those who "toiled in sweatshops and settled the West" were the factory workers of America’s industrial revolution and the pioneers of Manifest Destiny. The "the lash of the whip" is both an obvious reference to slavery and, perhaps, a sly reference to a line in Abraham Lincoln’s second inaugural ("every drop of blood drawn with the lash shall be paid by another drawn with the sword"). Concord and Gettysburg and Normandy and Khe Sanh were momentous battles of the Revolutionary War, The Civil War, World War II , and Vietnam War, respectively.

…As for our common defense, we reject as false the choice between our safety and our ideals. Our Founding Fathers, faced with perils we can scarcely imagine, drafted a charter to assure the rule of law and the rights of man, a charter expanded by the blood of generations.

Obama’s reference to a false "choice between our safety and our ideals" is almost certainly meant to echo Benjamin Franklin’s famous dictum that those who "give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." The main peril faced by our Founding Fathers—Franklin among them, of course—was defeat and punishment at the hands of the British. The "charter" they drafted, the "charter expanded by the blood of generations" throughout American history, is the Constitution of the United States.

…Recall that earlier generations faced down fascism and communism not just with missiles and tanks, but with sturdy alliances and enduring convictions. They understood that our power alone cannot protect us, nor does it entitle us to do as we please.

Here Obama refers to American victories in World War 2 (over fascism) and the Cold War (over communism), both of which were achieved not only through force of arms but also through effective diplomacy—the Grand Alliance with Britain, the Soviet Union, China and France in World War 2, and the NATO alliance of Western powers against the Soviet bloc in the Cold War.

…This is the meaning of our liberty and our creed—why men and women and children of every race and every faith can join in celebration across this magnificent mall, and why a man whose father less than sixty years ago might not have been served at a local restaurant can now stand before you to take a most sacred oath.

These words were perhaps Obama’s most direct (yet still fairly subtle) reference to the profound racial significance of his election as President of the United States. Throughout the Jim Crow era, Washington, DC was essentially a Southern city—which is to say a segregated city. As late as the early 1960s, when Martin Luther King came to the city leading the March on Washington, the most admired black man in America was still only able to stay and eat in certain establishments inside the city’s African-American districts.

…So let us mark this day with remembrance, of who we are and how far we have traveled. In the year of America’s birth, in the coldest of months, a small band of patriots huddled by dying campfires on the shores of an icy river. The capital was abandoned. The enemy was advancing. The snow was stained with blood. At a moment when the outcome of our revolution was most in doubt, the father of our nation ordered these words be read to the people: "Let it be told to the future world…that in the depth of winter, when nothing but hope and virtue could survive…that the city and the country, alarmed at one common danger, came forth to meet [it]."

America. In the face of our common dangers, in this winter of our hardship, let us remember these timeless words. With hope and virtue, let us brave once more the icy currents, and endure what storms may come. Let it be said by our children’s children that when we were tested we refused to let this journey end, that we did not turn back nor did we falter; and with eyes fixed on the horizon and God’s grace upon us, we carried forth that great gift of freedom and delivered it safely to future generations.

Obama closed his speech by invoking the bitter winter of 1776, which George Washington and his soldiers spent in camp at Valley Forge, Pennsylvania. American prospects in the Revolutionary War at the time looked bleak, as Washington’s men shivered and starved through the long winter knowing that they would soon have to go into battle against a fearsome British Army that regarded each and every one of them as a traitor to the crown.

The most famous quotation to emerge from the ordeal at Valley Forge was, interestingly, one that Obama chose not to use—Thomas Paine’s declaration that "These are the times that try men’s souls: The summer soldier and the sunshine patriot will, in this crisis, shrink from the service of his country; but he that stands it NOW, deserves the love and thanks of man and woman." While our own predicament as Americans facing difficult circumstances in early 2009 can hardly compare to the hardships endured at Valley Forge, Obama’s choice to end his inauguration by invoking the nation-making struggles of our forebears was almost certainly offered in the hopes of restoring a sense of national unity and purpose similar to that fostered by George Washington two centuries ago. If Obama succeeds in that, he will surely join Washington in the pantheon of great American presidents.