When they began to march, the crowd spanned several blocks: all in an effort, they say, to stand up against immigration laws that are scheduled to hit the senate floor in Washington next week.
The House already passed bill 4437 making it a felony to be in the US illegally, and punish employers who do not check the legal status of all employees.
This week, the Senate will consider a companion bill and other immigration reforms.
The President says he wants a more balanced approach... but, he is clear that he does not support amnesty for those who enter the US illegally.
Estel Gutierrez, a liaison for the Mexican government, says many protesting Saturday afternoon came to the US for a good reason.
"The American dream, basically. We're here to do a job and we bring a lot to the country. That's why it's diverse and in addition to that, when it comes to political power, we're a growing force."
Gilbert Cortez is an American citizen.
Born in Texas, he says he served during the Korean War and came home with a purple heart.
"It's a well known situation that immigration has become a problem. But, it is a problem that needs to be discussed. And, it needs to be a discussion that does not pit one group against each other."
He, like many others here, say they're torn.
Amelia Chavez says so many are legal citizens, but admits they are not far removed from those who aren't.
"I'm a US citizen and my sister is not. I guess what they're trying to say is the US citizens are supposed to tell them to go away. How are we going to do that if they're our family?"
The President says he supports reform to allow a temporary worker program that would match workers with US employers legally and then those people would then be considered for citizenship.