President Barack Obama is visiting Africa on a mission to make up for lost time.

Lagging behind former U.S. presidents Bill Clinton and George W. Bush, as well as China, in engaging sub-Saharan Africa, Obama has assembled a weeklong, three-country itinerary to begin taking a more active role in pushing U.S. investment and strengthening democratic institutions on the continent.

He arrived this evening in Senegal to start a trip that also will take him to South Africa and Tanzania. The visit is his first to the region as president since a one-day stop in Ghana in 2009. The itinerary puts him in the west, south and east of the continent while avoiding stops in Nigeria, which has been beset by human rights and corruption issues, and Kenya, where he has relatives. “There are other countries getting in the game in Africa - - China, Brazil, Turkey,” White House deputy national security adviser Ben Rhodes said before Obama departed Washington. “If the U.S. is not leading in Africa, we’re going to fall behind in a very important region of the world.” Obama is on the continent as former South African President Nelson Mandela, 94, who inspired the U.S. president’s early political activism, lies critically ill in a Pretoria hospital where he’s been fighting a lung infection since June 8. Mandela’s death would upend Obama’s schedule. The week’s events are designed to encourage U.S. trade and infrastructure development as well as more traditional goals of disease prevention and treatment and food security. Economic Opportunities American companies see a growing economic opportunity in Africa. U.S. merchandise exports to the 49-country region were $21 billion in 2011, up 23 percent from 2010, according to the Office of the U.S. Trade Representative. Imports from sub-Saharan Africa were worth $74 billion in 2011, up 14 percent from 2010. Most of that, about $60 billion, was crude oil. “The Obama administration doesn’t want the military engagement and drone bases to be the takeaway legacy that they have in Africa,” said Jennifer Cooke, director of the Africa Program at the Center for Strategic and International Studies, a Washington policy center. That’s the risk unless he develops a “countervailing message of economic engagement, democratic engagement,” she said. Among other actions, the U.S. is setting up a drone base in Niger and has provided training for troops in Mali in the past. The subtext of his itinerary, Cooke said, is “we need to be cultivating partners who will be friendly to us, whether it’s in the commercial side, the diplomatic side or ultimately the security side.” Trade Emphasis The new U.S. Trade Representative, Mike Froman, will accompany Obama, along U.S. with officials from the Overseas Private Investment Corp. and the Export-Import Bank of the United States, and Raj Shah, the administrator of the U.S. Agency for International Development. “There’s a huge demographic dividend waiting to be exploited” by the U.S. in Africa, said Haroon Bhorat, an economics professor at the University of Cape Town. “You’ve got dynamic opportunities that are being exploited, as you know, by China, India and other economies. So, to some extent, the U.S. has a foothold already, but recognizing that these are new and dynamic opportunities, both now and in the future, is critical.” In Tanzania’s fast-growing metropolis of Dar es Salaam, the last stop of the tour, Obama will convene a roundtable of company executives and promote U.S. investment in electrification projects. He also will tour the former slave house at Goree Island in Senegal. Robben Island In South Africa, he’ll tour Robben Island, where Mandela was imprisoned for 18 years during apartheid, and hold a town-hall style Young African Leaders Initiative meeting in Soweto. He’ll address the African continent from the University of Cape Town, where Robert F. Kennedy in 1966 delivered his anti-apartheid “ripple of hope” speech. Africa was a second-term focus for Obama’s immediate predecessors. Clinton visited twice. His 1998 trip covered six countries and represented the most extensive trip to sub-Saharan Africa by any U.S. president. His 2000 trip to two countries made him the first U.S. president to visit more than once while in office. Clinton signed the African Growth and Opportunity Act, a trade agreement with countries in sub-Saharan Africa. Bush, whose administration took U.S. spending on Africa to new levels, made a six-country visit in 2008 and a three-country stop in 2011 after he left the White House. His Africa legacy includes Pepfar, a $15 billion commitment to prevent and treat AIDS infections, credited with saving or extending millions of lives on the continent. Returning Focus Obama, 51, was largely occupied in his first term with the U.S. financial crisis, wars in Iraq and Afghanistan and a foreign policy pivot toward Asia. A year ago, he issued a policy directive on sub-Saharan Africa calling for expanded economic growth and pressing for stronger democratic institutions. In March, he met at the White House with Senegal’s President Macky Sall as well as the leaders of Sierra Leone, Malawi and Cape Verde. Still, Africans have been disappointed with Obama’s level of engagement because of his status as the first black U.S. president and because of his direct family connections there, said Mwangi Kimenyi, a senior fellow and director of the Africa Growth Initiative at the Brookings Institution, a Washington policy center. “Africans were very excited when President Obama was elected and they expected different engagement than in the past,” Kimenyi said. “On the policy side, Africans have been largely disappointed.” Compared with Obama’s visits, China’s top leaders have made more than 30, Kimenyi said, and the U.S.-Africa relationship is still defined by Clinton and Bush. Even so, Kimenyi said, “There’s excitement in the continent” and Obama is “still someone that Africans see as one of theirs.”