The article, "Statehood and the Equal Footing Doctrine: The Case for Puerto Rican Seabed Rights," was published in the Yale Law Journal in 1979, when it appeared that Puerto Rico might pursue statehood. Sotomayor was an editor of the Ivy League publication before receiving her law degree from Yale that year.

Sotomayor notes that other states didn't maintain rights to sea floors before joining the union. But she argued for a new historical analysis of the equal footing doctrine that prevents states from receiving powers other states do not have.

"The island's dearth of land-based resources and its ongoing economic stagnation and poverty, coupled with the possibility of offshore oil and mineral wealth, will create political pressures for Puerto Rico to demand exclusive rights to exploit its surrounding seabed in an area ranging from nine to 200 miles into the sea," Sotomayor wrote.

"The American experience with colonialism in the early half of this century has left the United States with responsibility for several small, economically poor dependencies," Sotomayor wrote. "Some of these, like Puerto Rico, may seek statehood unless they are accorded a greater measure of self-government. Accommodations between the federal government and an incoming state such as Puerto Rico, involving, inter alia, rights to the seabed, could help the new state to overcome its economic problems."

Sotomayor wrote that Supreme Court decisions about the equal footing doctrine "retain their precedential value," but argued that the court never explicitly decided whether the doctrine prevents Congress from granting disproportionate seabed rights to an incoming state.

President Barack Obama noted Tuesday as he introduced Sotomayor as his nominee that her parents had moved from Puerto Rico during World War II.