It may fairly be said that when it comes to background and experience, no presidential election in United States history has presented such a sharp contrast between the two leading candidates as does the one to be decided Nov. 4.

Sen. John McCain, D-Ariz., 72, is a career military man from a decorated family who has served in the Congress since his rival was 21 years old.

Sen. Barack Obama, D-Ill., 48, was born along America’s most distant shores and emerges from a family background unlike any other presidential candidate to take center stage.

John McCain is the son of a son of a Navy veteran. He graduated from the U.S. Naval Academy in 1958 and served in the Navy for 23 years. In the Vietnam War he flew dozens of bombing missions against the Communist North Vietnamese before being shot out of the sky. He spent nearly six years as a prisoner of war.

Eight years after his release he was elected to Congress, first as a representative and later as a senator, replacing GOP standard-bearer Barry Goldwater in 1986.

He is known as a maverick lawmaker who speaks candidly on the issues and crosses party lines to achieve his goals. In 2002 he joined with liberal Democrat Russ Feingold to pass campaign finance reform. In 2007 he co-sponsored an ultimately unsuccessful immigration reform measure with Democrat Ted Kennedy. Despite McCain’s maverick reputation, a Washington Post tally shows he voted with the Republican Party leadership 88 percent of the time in the current Congress.

In 1987 McCain was one of five lawmakers who improperly met with federal banking regulators on behalf of Charles Keating, Jr., the owner of a troubled savings and loan who was seeking lenient treatment from the government. Others were held more culpable than McCain. He was issued a mild rebuke from the Senate Ethics Committee in 1991.

This is McCain’s second presidential run. He was an early favorite in 2000, winning support for his Straight Talk Express campaign tour and taking the New Hampshire primary before George W. Bush won the nomination.

McCain’s Senate career included several years as chairman of the powerful Senate Commerce Committee. He remains on the Commerce Committee, as well as on Armed Forces and Indian Affairs, the last an important role for his state of Arizona.

Barack Obama was born in Hawaii and spent many of his early years outside of the United States. He was raised in Indonesia and Hawaii by his mother, an Anglo-American with roots in Kansas, and his Indonesian stepfather. Obama’s father is a black native of Kenya.

Obama became the first African-American president of the Harvard Law Review and graduated from Harvard Law School in 1991.

Upon graduation he returned to Chicago, where he had first lived in 1985. While practicing law Obama became involved in urban ward politics and civil rights issues, and in four years was elected to the Illinois State Senate.

After four terms Obama topped GOP candidate Alan Keyes to replace Republican U.S. Sen. Peter Fitzgerald.

In the state Senate, Obama worked to pass an ethics reform bill in a state plagued by political scandal.

Obama’s rhetorical and political skills have won him widespread admiration and success, yet his legislative record is slight.  In the U.S. Senate, Obama co-authored a measure that makes public a list of all recipients of federal funding, addressing concerns of secret earmarks and patronage. He also authored a bill in 2007 that would have blocked the troop surge in Iraq. He has consistently called for a redeployment of the troops in Iraq.

A Washington Post tally shows he voted with the Democratic Party leadership 96 percent of the time in the current Congress.

One of Obama’s major financial supporters, Chicago real estate developer Tony Rezko, has been convicted of influence-peddling in a matter related to Illinois politics but not linked to Obama.

This is Obama’s first presidential run.

In the U.S. Senate he is a member of the Foreign Relations, Homeland Security, Veterans Affairs and Health, Education and Labor and committees.