Benjamin N. Cardozo sat on the Supreme Court from 1932-1937, where his greatest achievement may have been laying down a foundation for a broad interpretation of the Commerce Clause. However, law students may know him better for his New York Court of Appeals opinions in Palsgraf, Wood v. Lucy, or Jacob & Youngs v. Kent. However, what brings him to the forefront today is his familial background.
Cardozo was a Sephardic Jew, which means that his ancestry is from North Africa or the Iberian Peninsula, rather than Eastern Europe, like us Ashkenazi Jews. Specifically, Cardozo's ancestors were from Portugal, and immigrated to the British colonies in the mid 18th century, before the Revolutionary War.
Admittedly, unlike Sotomayor, Cardozo was not a first generation American. Nor did he grow up in poverty, with a Vice-President of the New York Stock Exchange for an uncle and a judge for a father. However, this should not eclipse the fact that Cardozo could trace his family directly back to Portugal. Indeed, there is no question that Cardozo was a Portuguese American. The real question is whether that counts as Hispanic.
The United States Census Bureau does not consider Portuguese Americans to be "Hispanic," nor does the U.S. Office of Management and Budget. However, the U.S. Department of Transportation and the Small Business Administration, in addition to other federal, state, and municipal agencies, do recognize Portuguese under the umbrella term of Hispanic.
So perhaps it would be more accurate to say that Sotomayor would be the first non-white Hispanic on the Supreme Court.
In the end, whatever we call Sotomayor's ethnicity shouldn't matter. She would bring to the court a personal background and experience severely lacking.