However, the moment was almost ruined by his gaffe-prone Vice-President, Joe Biden.
Mr Biden was overheard whispering “This is a big f***ing deal” to Mr Obama right before the President signed the bill at the White House ceremony.
The President did not have any visible reaction, and went on to deliver his own profanity-free speech.
The Bill expands government health programs and subsidies for millions of Americans to buy private insurance.
It was all-but dead a few months ago after a series of Republican electoral victories, and Mr Obama was forced to off his trip to Australia to fight for its survival.
He managed to win over the doubting members of his own party for the Bill to squeak past the House of Representatives on Sunday.....(more after the jump)