Obama and Clinton Rally in Unity

The rally will be the first time the former rivals have shared a stage in public since Obama clinched the Democratic nomination earlier this month and began trying to mend the rifts caused by their epic 16-month campaign struggle.

The Illinois senator has tread cautiously in courting Clinton and her millions of supporters, including some still angry about the outcome of the Democratic race, as he tries to unify Democrats for November's election race against Republican John McCain.

He told reporters earlier this week he hoped the joint appearance in New Hampshire signaled an active role for the New York senator in his White House race.

"I want her campaigning as much as she can," Obama said. "She was a terrific campaigner. She, I think, inspired millions of people, and so she can be an extraordinarily effective surrogate for me and the values and ideals we share as Democrats."

Clinton, who returned to her Senate duties in Washington this week for the first time since dropping out of the Democratic race on June 7, offered strong praise for Obama during two public appearances on Thursday.

"I have seen his passion and determination and his grit and his grace," she told a nurse's association in Washington, asking them to back Obama.