The dispute echoed similar debates that have occurred for more than a decade not only in Congress but at state and local levels.
Twenty-seven states have passed statutes declaring English their official language.
The Senate's debate reflected growing concerns among many lawmakers about the need to reinforce common ties among citizens. An estimated 47 million people in the U.S. speak a language other than English at home.
"We are not a nation based on race," Sen. Lamar Alexander (R-Tenn.) said in support of the "national language" amendment. "We are a fragile idea based on a few common principles and our national common language."
But some interpreted the amendment as an attack on Latinos. And in a chamber that prides itself on civility, that concern prompted unusually harsh language.
"I believe this amendment is racist," Minority Leader Sen. Harry Reid (D-Nev.) told Sen. James M. Inhofe (R-Okla.), the measure's sponsor. "I think it's directed basically to people who speak Spanish."
Inhofe, who speaks Spanish, strongly denied the charge, calling it "ridiculous."