The U.S. Census Bureau says America’s population reached the 300 million mark today, and reports say that symbolic 300-millionth person may have been an immigrant, not a newborn. Iowa Senator Chuck Grassley says it’s a milestone of which all Americans should be proud.

“It’s respectful of the United States not only being a good place to raise families and people being born here, but in the case of immigrants, people that want to come here because of the opportunity that our country offers,” he says.

The U.S. population reached 200 million in 1967. The Census Bureau estimates there’s a birth every seven seconds in the U.S., a death every 13 seconds, and a new immigrant every 31 seconds.

“We have always had our doors open and we oughta’ keep our doors open to legal immigrants, so we welcome legal immigrants,” Grassley says. “We’re going to do all we can to keep illegal immigrants out including the building of the fence that Congress authorized last month and the president signed.”

About three dozen Iowa National Guard soldiers reported for duty Monday near the Mexican border. They will help the California Guard with a border security mission in a non-combat role. Grassley says those who say the deployment is a political move may need to reassess their logic. “If you are finding fault with it, it’s a way of saying that it’s okay for illegal people to come into the country. It’s been going on for 25 years so it’s wrong to blame one president over another. The only thing is, this president is doing something about it and that’s signing the bill establishing the fence,” Grassley says.

The Iowa Guard mission on the border is expected to last between six months and two years.