The Democratic-dominated Congress convenes Tuesday to confront perhaps the worst economic crisis since the Great Depression and to grapple with a hugely ambitious agenda set by President-elect Barack Obama.

The opening day of a two-year session is typically more ceremony than substance, and Congress often recesses until the new president takes office or after the State of the Union address at the end of January.

This year, however, with the economy in a worsening recession, Democrats are promising swift action on an as-yet-unveiled $775 billion economy recovery program that is the first order of business for the Obama administration.

"We will hit the ground running ... to address the pain being felt by the American people," House Speaker Nancy Pelosi, D-Calif., promised Monday as she welcomed Obama to her office.

For the first time in 16 years, Democrats control both houses of Congress and welcome one of their own to the White House. That foreshadows a productive session, particularly if Obama can muster Republican support for his initiatives, as he is seeking.