When our Founding Fathers signed the Declaration of Independence in 1776, they had plenty of reasons for wanting to break away from England and its king.

The Declaration begins with political poetry: We hold these truths and so on. The bulk of the document, however, outlines a long train of abuses and usurpations. Its a list of grievances.

One of the grievances speaks to a 21st-century concern: The Declaration attacks King George for cutting off our Trade with all parts of the world.

Most Americans probably read the Declaration of Independence at least once in their lives, often when theyre kids and a history teacher makes them do it. That isnt enough: The Declaration describes the purpose of our nation, and from time to time we ought to refresh our memories.

I keep a pocket copy of the Declaration and the Constitution in the glove box of my pick-up truck. On days when Im working my farm and discover that I have a few spare minutes, I pull out this little booklet and review its pages.

Independence Hall

Whatever your own habits, this is a great time of year to re-read the Declaration and think about what it means: Its a perfect way to celebrate our countrys birthday.

This year, Im struck by that passage about trade.

Were once again in the grip of a great debate over the economic costs and opportunities of moving goods and service across borders.

Our Founding Fathers wanted free trade with the world. Their major exports came from agriculture: tobacco, flour, rice, and more.

The King of England had a different idea. He believed in mercantilism, which favored high tariffs and said that governments should restrict or forbid colonies from trading with rival nations.

Following the French and Indian War, which concluded in 1763, trade tensions worsened. Combined with a series of other frustrations, they finally became explosiveand in 1776, the colonists issued the Declaration of Independence.

We see a similar dispute in our politics today: Economic isolationists are modern-day mercantilists who want to focus on domestic production and limit our trade. The rest of us are more like the Founding Fathers: We see global trade as a national necessity that expands choice and creates prosperity here at home.

As a farmer in the Pacific Northwest, I cant imagine life without trade. I grow mainly alfalfa seed, and something like 40 percent of all the alfalfa and alfalfa seed in my region ships to customers in other countries. Last March, in fact, we set a new record for alfalfa-hay exports, with demand in China driving much of it. A decade ago, we hardly sold anything to China.

Trade with China, in fact, dates to Americas Founding era. In 1784the year after we signed a peace treaty with the Britisha commercial ship left New York harbor. The Empress of China, as it was called, became the first American ship to arrive in China. It exchanged silver for tea.

But free trade was more than a commercial benefit: It was indispensible to the success of the American Revolution.

The late historian Barbara Tuchman tells the story of what happened a little more than four months after July 4, 1776.

A brig flying the flag of the Continental Congress sailed to St. Eustatius, a Dutch island in the Caribbean that was a hub of free trade. The Andrew Doria and its crew sought guns and gunpowder, which of course were essential to the success of General Washingtons army.

Andrew Doria

As the ship arrived on November 16, the Dutch governor ordered cannons to firenot in hostility, but in recognition of American independence. This is believed to be the first time a foreign power formally acknowledged American sovereignty, and it gave Tuchman the name for her book: The First Salute.

The Andrew Doria brought home military supplies for the war effort, in a compelling example of how trade with all parts of the world has helped Americans from the earliest of times.

Among the items the crew left behind on St. Eustatius, for all to read and admire, was a copy of the Declaration of Independence.