WASHINGTON (September 8, 2009)--Justice Sonia Sotomayor took her seat Tuesday on the U.S. Supreme Court in front of a packed courtroom that included President Barack Obama and Vice President Joe Biden.

The ceremony Tuesday was just for show.

Sotomayor and the rest of the court will return Wednesday for the argument in a key case about campaign finance law.

Last month, Sotomayor, 55, became the first Hispanic and third woman to be a justice.

She took the oath again Tuesday in a ceremony by which the court formally welcomes its newest member.

Attorney General Eric Holder presented Sotomayor's ivory-colored commission from Mr. Obama.

Chief Justice John Roberts administered the oath of office, after which Sotomayor took her seat at the end of the bench to Roberts' left, next to Justice Stephen Breyer.