Before arriving on the Island in July, I drove through National Military Park where monuments from northern and southern states dominate centuries-old fields of brilliant green, soon to turn golden, and where wild native plants populate the fields buffered by rock walls and split rail fences, looking much as they were in 1863. I could only think of the horrific injuries suffered from those ghostly cannons which stand silent, reminding us of those who witnessed so many lives lost and the overwhelming task performed by the townspeople who had to bury the dead.

I live minutes from where the Battle of Gettysburg took place July 1 to July 3, 1863. It was here where soldiers who made the ultimate sacrifice to preserve the Union are buried in the National Military Park, characterized by President Lincoln as, “those who gave their last full measure of devotion.” This battle became known in history as the High Water Mark, or turning point in the Civil War that shifted momentum to the Union Army. There will always be revisionists and those who paint a more cynical picture of the war, who will challenge the abolition of slavery as its objective, who will offer new stories. But ultimately the outcome makes this battlefield a place of reverence.

The three-day battle resulted in 41,000 casualties and led to the freedom of over four million slaves. Two years later, after an initial exchange of notes and agreements on the surrender of the Army of Northern Virginia, Gen. Robert E. Lee agreed to meet with General Ulysses Grant at the house of Wilmer McLean in the village of Appomattox Courthouse. The terms of surrender were signed on April 9, 1865, by General Lee, formally ending the Civil War. Post Appomattox produced Jim Crow laws that remained for a century, vestiges of which remain today. It is important to draw parallels and lessons as we honor those Lincoln immortalized in his Gettysburg Address. And though the 150th anniversary of the war continues to evoke powerful emotions, its fundamental truth is the same: “A house divided against itself cannot stand.”

President Lincoln arrived at Gettysburg four months later, disembarking from the presidential train on Nov. 18,1863, accompanied by his trusted part-time valet and messenger, William H. Johnson a free African American. As he walked to Wills House to put the finishing touches on his immortal speech, The Gettysburg Address, throngs of people assembled there to greet him amid astounding devastation. One can only imagine the heartache and what he knew his duty to be — to honor those Union soldiers in The Army of the Potomac who had given “their last full measure of devotion.”

In the space of 272 words on Nov. 19, 1863, Mr. Lincoln made a speech that has as much relevance today as it did 150 years ago when he first uttered the words to a bereaved nation after a critical Union victory in the Battle of Gettysburg. The president faced a Union that was in danger of breaking up, where North and South were in profound disagreement over slavery at a time when thousands of lives were being lost. He possessed a fundamental belief that it was possible to have “a new birth of freedom,” for the enslaved and the slave owner. He recognized the moral hazard of a nation adrift amid disunity and called on the people to unite after three days of horrific losses during the battle. Mr. Lincoln knew he would stand alone on that new hallowed ground which he would dedicate, and that his words had to mean something. And though there was imperfection in the system — African American soldiers could not be buried at the National Cemetery because of segregation laws — they refused not to be a part of this great American experiment of brotherhood, tolerance and love of country.

Many are unaware that there is another cemetery in Gettysburg that we celebrate, the Lincoln Cemetery on Long Lane. It is Gettysburg’s historical African American burial ground which is the final resting place for the 30 Civil War veterans of the United States Colored Troops (USCT). Though two Civil War veterans of the USCT (Pvt. Charles H. Parker and Pvt. Henry Gooden) were buried in the National Cemetery in the 20th century, long after the war ended, the majority were moved from the York Street graveyard and re-interred in the Good Will Cemetery in 1867, the oldest section of what is now the restored Lincoln Cemetery. It was Betty Myers, a retired school teacher and a woman with an indomitable spirit who raised money to reclaim the grave sites from a hospital parking lot.

Each year in November we pause to reflect on the meaning of the Gettysburg Address and the war and why they are still important to us. This was a defining moment for our nation and a remarkable moment of redemptive racial reconciliation and validation of those common values that Lincoln believed we could share. Not dissimilar to challenges we face today at a time when our nation is attempting to extricate itself from war, addressing challenging economic issues and seeking to eliminate renewed racial conflict. Our leaders are called on, just as Lincoln was, to find common ground and come together as a nation to solve these enormous problems.

And though we would be loathe to equate our present political problems with that of the Civil War, indeed the current governing administration cannot help but be inspired by and draw sustenance from a courageous President Abraham Lincoln and the people themselves who sought and received from him a reclaimed hope and spirit, giving free men and slaves alike a vision that a nation conceived in liberty and dedicated to the proposition that all men are created equal was an achievable goal.

From the moment that Sen. Barack Obama stood on the steps of the Old State Capitol site in Springfield, Ill., in 2007 and announced his candidacy for President of the United States, as had Abraham Lincoln 99 years earlier in 1858, he created connections that would become the bedrock values of his administration. His message was clear: “You came here because you believe in what this country can be. In the face of war, you believe there can be peace. In the face of despair, you believe there can be hope. In the face of a politics that’s shut you out, that’s told you to settle, that’s divided us for too long, you believe we can be one people, reaching for what’s possible, building that more perfect union.” Sound familiar?

President Obama has been under siege since first elected and there have been times when one wonders if elections still have meaning. In spite of a rough reelection in 2012, the mission of unity resonates and remains. Our nation has risen to its greatest heights when we recognize our common humanity, see others as ourselves, as family and as neighbors; when we honor sacrifice, and above all place the common good of the nation above the narrowness of our own personal beliefs. When our energy is placed on solving the problems that confront us, we make progress. These are the lessons to be learned.

From Gettysburg to the White House, our nation continues to do the important business before us — to care for our veterans, honor those who made the ultimate sacrifice, and continue the work before us. Just as women, immigrants and African Americans played out their roles on those fateful days so many years ago in Gettysburg, and those that followed, today that vision requires we never compromise on those principles that define us as a people, that we pay attention to those who need our support, that we prepare youth for a global economy that will ensure our survival and prosperity, that we never forget we are best when we are one people, united.

Bettye Foster Baker lives in Oak Bluffs and Gettysburg, Pa. She formerly wrote the Oak Bluffs column for the Gazette.