*Obama will sign stimulus legislation Tuesday

*Congressional approval gives Obama much-needed boost

*Republicans say much of bill's spending "wasteful"

By Matt Spetalnick

CHICAGO, Feb 14 (Reuters) - U.S. President Barack Obama on Saturday hailed congressional approval of a $787 billion economic stimulus bill as a "major milestone on our road to recovery" and the White House said he would sign the legislation on Tuesday in Denver.

"I will sign this legislation into law shortly, and we'll begin making the immediate investments necessary to put people back to work," Obama said, savoring his biggest legislative victory since taking office on Jan. 20.

The Senate cast the final vote, 60-38, late on Friday, hours after the House of Representatives passed an identical bill, 246-183, capping weeks of arguing over how to best jolt the economy out of deep recession.

Obama and his fellow Democrats who control Congress failed to win over many Republicans, falling short of the broad bipartisan support he sought for the massive package of increased spending and tax cuts.

But Obama brushed off partisan bickering over the stimulus bill as "healthy differences of opinion."