The Fourth of July seems like a pretty straightforward holiday: We celebrate America’s independence and its commitment to freedom. But this year in particular it seems like the trouble is in the details.

As a Marine who was wounded in Iraq, I had a lot of time during my recuperation to think about what our nation’s values mean. I’ve always believed that America was not a perfect country but one that was on a path of improving itself and striving to live up to its cherished ideals. Our own Declaration of Independence only guarantees “the pursuit of Happiness,” after all, not happiness itself.

But some recent events have made me wonder how hard we are trying.

In Iraq and Afghanistan, we struggled to ensure that everyday people had the opportunity to vote, yet here at home we institute voter ID laws that raise significant barriers for some voters. We lamented the treatment of women in the Middle East, yet in America women still earn less than 80 cents for every dollar earned by men. We worked hard to convince the Shi’ites and Sunnis to work together, yet the reaction of some in our country to the Supreme Court’s ruling about same-sex marriage shows that not everyone considers all of God’s children to be equal.

America remains a work in progress. But we are striving to be what presidents Reagan and Obama have both called “the shining city on the hill.”

Just like anything else worth having in life, our American ideals require constant care and attention. In fact, our Founding Fathers envisioned that we could continue to take such action – that is why they designed a process for constitutional amendments, a system of checks and balances, and a vibrant democratic process. They understood that America will always be a work in progress, and that is a good thing.

Internationally, then, America must continue to lead by example, to show the world that we never stop striving. During my patrols in Iraq, I thought that freedom for Iraqis meant something as basic as not being persecuted by their government or harassed by insurgent forces. But it does not stop there. Freedom is woven into the fabric of our everyday lives: how we choose to worship, where we choose to live, what we choose to do.

President Abraham Lincoln said that, “The world has never had a good definition of the word liberty, and the American people, just now, are much in want of one. We all declare for liberty; but in using the same word we do not all mean the same thing.”

As we approach July 4, I’ve been thinking more about my own definition of our American ideals, trying to resolve the conflicting aspects of our diverse country.

The massacre of nine people at a church service in Charleston, S.C., is the most recent of a number of mass killings across our country. But I have wondered along with my friends why we hesitate to label the alleged shooter – or the killers in Aurora, CO., or Newtown, CT – as terrorists, when we feel so comfortable using that word to describe Muslims who commit violent acts. Maybe we shouldn’t label any of them and instead should spend more time trying to identify why some people become so disenfranchised that they commit these acts. Let’s not forget that the most devastating example of domestic terrorism, the Oklahoma City bombing, was committed by a white Christian.

The incident has also made me reflect on the way we as a country talk about our imperfect past. I think back to my high school mascot, Johnny Reb, a soldier carrying the Confederate flag. Before the mascot was replaced in 1988, I honestly had not given it much thought. But looking back, now I realize I was wrong. There is nothing pride-worthy about the Stars and Bars. It’s taken us too long to move on from that relic of our past.

Like any other veteran, I believe so strongly in our country and our ideals that I swore an oath to support and defend our Constitution against all enemies, foreign and domestic, and bear true faith and allegiance to that Constitution. I want every other American to experience, enjoy and benefit from the same freedoms and liberty as I do. Ultimately, I hope we can successfully encourage those same ideals around the world as well.

We continue to be that shining city, but only because we embrace the idea of an open society where encourage many different voices. As Americans, we are united in our belief that a successful society is one that embraces change, while at the same time ensuring basic freedom and equality for all. As Lincoln noted in the Gettysburg Address, our country was “dedicated to the proposition that all men are created equal.” That is who we must continually strive to be. That is freedom. And as an American, a veteran, and as someone who wants to see more equality in our communities, that is what I am thinking about this year.

Follow Justin Constantine on Twitter: