Representing the U.S.
Lance Brooks, Springfield, track and field (discus): The No. 1 discus thrower in the country, Brooks once worked seven jobs to pay for his training. The Millikin University graduate is ranked 34th in the world.
Kelci Bryant, Chatham, diving (3m synchro): After finishing fourth in Beijing, Bryant is looking to make the medal stand with partner Abby Johnston. The pair also finished fourth at the 2012 FINA World Cup.
Swin Cash, Chicago Sky, basketball: A gold medalist in Athens, Cash is trying to add to an impressive winning resume that includes two NCAA titles at Connecticut and three WNBA titles with Detroit and Seattle. Cash, traded to the Sky this year, badly wanted this honor after not making the 2008 team.
Tamika Catchings, Lincolnshire, basketball: The oldest member of the U.S. women's team at 33, the Indiana Fever star was Ms. Basketball of Illinois as a Stevenson High School sophomore in 1995 before moving to Texas.
Ellis Coleman, Oak Park, wrestling (60kg Greco-Roman): The youngest member of the U.S. wrestling team, Coleman, 20, became an Internet sensation last year when a video of him flipping his opponent — a move known as "The Flying Squirrel" — was posted on YouTube. A medal is a long shot, but he could garner some attention if he tries his acrobatic move in London.
Conor Dwyer, Winnetka, swimming (400 free, 800 free relay): The former Loyola Academy star made his first Olympic team last month by finishing second in the 400-meter freestyle and fourth in the 200 free at the trials. He won gold at the 2011 world championships as part of the 800 free relay.
Sylvia Fowles, Chicago Sky, basketball: The 6-foot-6 center averaged 13.4 points in Beijing, her first Olympics. She is on a women's team seeking an unprecedented fifth straight gold medal, and with Lisa Leslie retired, Fowles should play an even larger role.
Matt Grevers, Lake Forest, swimming (100 back, 400 free relay): The 2008 silver medalist overcame a major slump to earn an Olympic spot at the U.S. trials last month with the second-fastest time ever posted in the 100-meter backstroke. The Lake Forest High School and Northwestern graduate won the final in 52.08 seconds, making him a gold-medal favorite in London.
Dawn Harper, East St. Louis, track and field (100 hurdles): A surprise gold medalist in Beijing, Harper is looking to defend her title but will have to battle teammate Lolo Jones for the spotlight.
Jake Herbert, Northwestern University, wrestling (84kg freestyle): The most decorated wrestler in Northwestern history, Herbert won the Hodge Trophy in 2009 as the nation's top college wrestler and won a silver medal in the 185-pound class at the world championships later that year. He could factor into medal mix if the bracket breaks his way.
Andre Iguodala, Springfield, basketball: The first-time Olympian is being asked to reprise his role as a defensive stopper for the Philadelphia 76ers. With international play more wide open and often featuring smaller lineups, the role will be crucial.
Evan Jager, Algonquin, track and field (3,000 steeplechase): The Jacobs High School graduate broke the American steeplechase record in his first international competition. Despite having run only five races in his career, he has the eighth-fastest time in the world this year.
Grant James, DeKalb, rowing (men's eight): Grant and his twin, Ross, knew nothing about rowing when they were recruited to row for the University of Wisconsin after a coach spotted the 6-foot-5 twins in line at freshman orientation.
Ross James, DeKalb, rowing (men's eight): The James brothers, who expect to room together in the Olympic Village, are one of two sets of twins on the U.S. team. (The other is tennis players Bob and Mike Bryan.)
Amy LePeilbet, Crystal Lake, soccer: The defender is a graduate of Prairie Ridge High School.
Gia Lewis-Smallwood, Champaign, track and field (discus): The former Illini athlete attended Centennial High School.
Christina Loukas, Riverwoods, diving (3m springboard): She was a three-time state champion at Deerfield High School.
Tyler McGill, Champaign, swimming (100 fly): McGill beat out Ryan Lochte last month to secure a spot on the Olympic team. He won his first world championship medal last year — a bronze in the 100-meter butterfly — making a medal in London possible.
Candace Parker, Naperville, basketball: The former Naperville Central star won the Ms. Basketball of Illinois award three times before heading off to Tennessee, where she led the Volunteers to two national championships. She was on the gold-medal-winning U.S. team at the 2008 Olympics and plays for the L.A. Sparks in the WNBA.
Sean Rooney, Wheaton, volleyball: A former Pepperdine standout, Rooney is looking for a second gold medal in as many Games. If the U.S. intends to repeat, they'll need a strong performance from the 6-foot-9 outside hitter.
Wallace Spearmon, Chicago, track and field (200): The Chicago-born Spearmon comes to London looking for redemption for his performance in Beijing, where he finished third in the 200 meters but was disqualified for stepping out of his lane. Facing tough competition from good friend Usain Bolt and the other Jamaicans, he could factor into the medal mix.
Deron Williams, University of Illinois, basketball: The former Illini star returns to the Olympics in a quest for a second gold after being part of the "Redeem Team" that finished atop the medal stand in Beijing. Anything other than a gold will be unacceptable for the U.S. squad.
Bob Willis, Chicago, windsurfing: The only member of the U.S. windsurfing team not from California or Florida, Willis honed his sailing skills at the Columbia Yacht Club. He punched his ticket to the London Games with top finishes in Olympic regattas in London and Australia, making him a medal favorite.
Donald Young, Chicago, tennis: Young, 23, turned pro in 2004. Last year he broke into the ATP's top-50 ranking for the first time. He will play singles in London.
Sarah Zelenka, Itasca, rowing (women's pair): The former Lake Park High School basketball star qualified for the Games with a thrilling come-from-behind victory at the trials. Her trophy case includes a gold in the four boat at the 2011 world championships.
Representing other countries
Robert Archibald, University of Illinois, basketball: The Scottish center, who helped the Illini to back-to-back Big Ten titles in 2001 and 2002, will be playing in his first Olympics for Britain. He plans to retire after the games, ending a 10-year pro career.
Carolena Carstens, Glen Ellyn, taekwondo (49kg): The youngest competitor in her event, Carstens, 16, is representing her mother's native Panama. She was given a wild-card spot from her sport's international federation to compete.
Luol Deng, Chicago Bulls, basketball: The face of Britain's basketball team is one of the most compelling stories, repaying a country that offered his family political asylum from war-torn Sudan. That he is doing so with a torn ligament in his left wrist underscores his commitment and worries Bulls management.
Nikkita Holder, University of Illinois, track and field (100 hurdles): The former Illini star placed third in a tough Canadian field to earn her first trip to the Olympics. She finished sixth at the world championships last year.
Richard Oruche, Bensenville, basketball: A 6-foot-4 shooting guard, the Fenton High School and Northern Illinois alumnus will play for his native Nigeria. His selection to the team comes after a strong season with Portuguese club Academica.
Andrew Riley, University of Illinois, track and field (110 hurdles): The recent Illinois graduate caps off a spectacular college career by representing his home country, Jamaica, in London. In June, he became the first male athlete to win the NCAA 100-meter dash and 110 hurdles titles in the same year.
Jillian Schwartz, Lake Forest, track and field (pole vault): The Duke graduate competed for the United States in the 2004 Games but switched her competitive allegiance to Israel in 2009 because it offered her a better chance of qualifying for London.