FACTBOX: Sen. Biden. Democratic VP candidate

(Reuters) - Democratic presidential candidate Barack Obama has chosen Joseph Biden of Delaware, one of the longest-serving members of the U.S. Senate, as his vice presidential running mate for the November 4 election.

Here are some facts about the 65-year-old lawmaker, considered a leading expert on foreign affairs.

* Biden was first elected to the Senate in 1972, shortly before he turned 30, the minimum age. A month later, his wife and daughter were killed and two sons injured in a car crash. Biden considered giving up his Senate seat but party leaders helped persuade him to serve. He remarried five years later.

* With a liberal to moderate voting record, Biden heads the Senate Foreign Relations Committee and has been outspoken on international affairs. Although he backed the 2002 resolution to authorize the use of force in Iraq, he soon became a strong critic of the war and accused President George W. Bush of mishandling it.

* Biden's son Beau, a captain in the Army National Guard, is scheduled to be deployed to Iraq in October.

* A Roman Catholic originally from the key battleground state of Pennsylvania, Biden would bring to the ticket strong working-class roots that could help Obama connect with the blue-collar voters he has failed to attract.

* Biden is the son of a car salesman and is less well off than many of his Senate colleagues. While many lawmakers own or rent residences in Washington, Biden commutes by train from his house in Wilmington, Delaware, 80 minutes each way.

* Biden, a frequent guest on political talk shows who seems to relish debating, is seen by many political analysts as well-suited to the traditional role of a No. 2 -- attacking the rival candidate.

* Biden has acknowledged a tendency to talk too much and he has been prone to verbal gaffes. Last year, early in his own failed presidential campaign, Biden apologized after calling Obama "articulate and bright and clean" in an interview with the New York Observer. Obama said he did not take offense.

* When Biden was asked during a primary election season debate whether he possessed the discipline to be president, the famously loquacious senator responded with one word -- "yes" -- prompting gales of laughter from the audience.

* In his previous role as chairman of the Senate Judiciary Committee, Biden presided over two of the most controversial confirmation hearings for Supreme Court nominees, both conservative Republicans. Robert Bork was rejected while Clarence Thomas was narrowly confirmed.

* In 1987, Biden was seen as a rising young political star and ran for president. But he dropped out after charges of plagiarism in one speech and exaggerating his academic record. Biden said: "In my zeal to rekindle idealism, I made some mistakes."

(Writing by Thomas Ferraro and Caren Bohan, editing by John O'Callaghan)