Public records reveal some of the projects he sponsored as a state senator, from literacy programs and park improvements to drill team uniforms and jazz-appreciation events. They add up to more than $6 million.
But that covers just two of Obama's nearly eight years in the Illinois Senate.
While silent about Obama's spending in Illinois, his campaign has criticized Democratic presidential rival Sen.for withholding similar information about her years in the U.S. Senate.
Obama communications director Robert Gibbs said Thursday that her position should prompt voters to "ask why she doesn't believe they have the right to know she wants to spend their tax dollars."
Since entering the U.S. Senate and launching his presidential campaign, Obama has made a political issue of openness.
He voluntarily discloses the "earmarks" he adds to the federal budget; Clinton does not. He initially released only one year's worth of earmark information, but on Thursday he released his requests for the 2005 and 2006 federal budget years, too.
"I have been consistently in favor of more disclosure around earmarks," Obama said in a debate last month. "Now, keep in mind a lot of these are worthy projects in our states ... but I want to make sure that they're not done in the dark of night."
That disclosure, however, so far applies only to federal spending.
When Obama served in the state Legislature, from 1997 until late 2004, it was routine for money to be added to the annual budget for lawmakers to dole out. In most years, this was done without any public record of which legislator was sponsoring which grant, leaving no way to tell how Obama used his share of the money.
But for a couple of years, the state did link lawmakers and grants.
Records from that period show Obama sponsored a little more than $6 million in projects.
Of that, $2 million went to the Chicago Park District for projects ranging from adding or expanding parks to repairing fountains to building a running track.
Chicago schools got grants of $5,000 and $10,000 to buy computers, improve security systems or offer new programs. The transportation department got $200,000 for new stoplights.
Private organizations got money, too.
Neighborhood groups in the South Side district he represented were given grants, typically $15,000 or $20,000, for such projects as senior centers, park improvements and teen mentoring programs.
Obama was one of several lawmakers to direct money to the South Shore Drill Team, which tries to keep poor children away from drugs and gangs by involving them in dance and music. Obama's grant to them was $25,000.
He also directed $100,000 to the Museum of Science and Industry for an exhibit on the nature of time, and provided two $5,000 grants for groups promoting jazz appreciation.