Former President Barack Obama on Wednesday resurrected his campaign slogan of hope and change as he closed his foundation's first summit launching his post-presidency initiative to foster young civic leaders.Obama held the invitation-only summit in Chicago for 500 hand-picked young leaders from 60 nations and 27 US states to share ideas and hear speakers, including Britain's Prince Harry, along with artists, chefs, activists and politicians.The 44th US president urged patience as he told participants they would help shape the Obama Foundation's emerging plans to encourage grassroots solutions to problems ranging from mass incarceration to income inequality."People always misunderstood sometimes that the slogan we used, hope, the audacity of hope. Hope does not mean that tomorrow everything's going to be better," Obama said. "Change is possible if we put our shoulder to the wheel. But it doesn't happen overnight."Obama did not mention President Donald Trump, who has sought to dismantle many of Obama's policies, including his signature domestic policy achievement, the Affordable Care Act, and deportation protections for young immigrants.