I went to an immigration protest demonstration in Union Square briefly today, although I didn’t boycott work — it was my first day back after my two-week vacation, so I went on my lunch break.

Immigration is a very complex issue, and nowhere more so than in the United States, a country that was built and populated (some would argue “invaded,” with some justification) by immigrants.

The nationwide demonstrations and protests were intended to raise awareness of the contribution made to the U.S. economy by immigrants — including an estimated 11.5 million illegal immigrants — as controversial new immigration legislation makes its way through Congress.

Personally, I think the American economy would grind to a screeching halt without illegal immigrants — so much of the country’s underlying infrastructure relies on undocumented workers, who are often forced to work for considerably less than the minimum wage.

For many Americans, the idea of “illegal immigrants” conjures images of hordes of central and south Americans swarming across the Mexican border in the dead of night. And it’s true that the majority of illegal immigrants in the United States enter the country in this way.

But having been an illegal immigrant myself briefly in the past because of a “Catch-22” style administrative error by the Bureau of Citizenship & Immigration Services, I know first hand that it isn’t always as simple as that. These administrative errors are not uncommon, but they are always stressful for the individual concerned.

I was lucky — in addition to being white, educated, single and employed, I could also afford to spend the significant time and money (several thousand dollars) on legal processes necessary to rectify their error.

Ultimately, though, immigration is not a single nation’s problem; individuals will always seek the best quality of life possible for themselves and their families — it’s just human nature. Until there is a more equitable global distribution of wealth, people will continue to migrate from poorer countries to richer countries. And if they can’t do it legally, they will continue to find alternate routes.