On July 2, 2015, he announced that he would be joining the race for the Democratic nomination for president, but stepped down from running in the primaries on October 20, 2015, stating that he was "not comfortable" with many political positions from the party's leadership.

[5] The second of four children and the older son, he grew up in a military family, moving frequently as his father's career in the United States Air Force required.

The family crisscrossed the country, living in Missouri, Illinois, Texas, Alabama, Nebraska, California, and Virginia, as well as in England, where his father was an exchange officer with the Royal Air Force.

Webb's 2004 book Born Fighting: How the Scots-Irish Shaped America details his family history, noting that his ancestors fought in every major American war.

After graduating from high school in Bellevue, Nebraska, he attended the University of Southern California on a Naval Reserve Officers Training Corps scholarship from 1963 to 1964[8] and he also was a member of Delta Chi.

[11] After his medical retirement from the Marine Corps due to injuries suffered in Vietnam, Webb enrolled in law school at Georgetown University where he earned a Juris Doctor and received the Horan Award for excellence in legal writing.

On July 10, 1969, while participating in a company-sized search and destroy operation deep in hostile territory, First Lieutenant Webb's platoon discovered a well-camouflaged bunker complex that appeared to be unoccupied.

Despite the smoke and debris from the explosion and the possibility of enemy soldiers hiding in the tunnel, he then conducted a thorough search that yielded several items of equipment and numerous documents containing valuable intelligence data.

By his courage, aggressive leadership, and selfless devotion to duty, First Lieutenant Webb upheld the highest traditions of the Marine Corps and of the United States Naval Service.

On 9 May 1969, during Operation Muskogee Meadow, a six-man reconnaissance patrol from First Lieutenant Webb's platoon was ambushed and temporarily pinned down by a large North Vietnamese Army force concealed in a tree line four hundred meters in front of Company D's night defensive position.

Then, consolidating his platoon, he initiated a sudden, vigorous attack which routed the enemy soldiers from their bunkers, disorganized their fire plan, and forced them to retreat from the area.

His determination and bold fighting spirit inspired all who observed him and were instrumental in saving the lives of at least two Marines and undoubtedly thwarting the enemy's plan to launch a major attack against his unit's night position.

By his leadership, extraordinary courage, and unflagging devotion to duty at great personal risk, First Lieutenant Webb upheld the highest traditions of the Marine Corps and of the United States Naval Service.

In one segment, he discussed how hard it was to adjust to arriving in Vietnam: "We stepped off an air conditioned plane, where I just watched a first-run movie, and you know, this German stewardess says, 'Have a nice war.

"[16] In a November 19, 2006 appearance on Meet the Press, Webb told host Tim Russert, "I'm one of these people who – there aren't many of us – who can still justify for you the reasons that we went into Vietnam, however screwed up the strategy got.

Webb taught at the Naval Academy and was criticized for a 1979 article published in Washingtonian magazine, titled "Women Can't Fight"[19] (see "2006 Senate campaign" below).

"[22] In a 1990 New York Times opinion piece, Webb opposed further U.S. military escalation in Saudi Arabia during Operation Desert Shield citing lack of a coherent strategy and consent from the United States Congress.

"[24]During the 2004 presidential campaign, Webb wrote an op-ed piece for USA Today in which he, as a military veteran, evaluated the candidacies of John Kerry and George W. Bush.

[32] Five female graduates of the United States Naval Academy held a press conference, decrying Webb's 1979 article, "Women Can't Fight."

"[36] According to an article on Raw Story, the conservative website CNS News cited a case in Nevada in which a Cambodian mother was arrested for a similar act.

Although the margin was narrow – less than half of 1% of the total vote and therefore small enough under Virginia law to allow demanding a recount – Allen stated that he would not challenge the result.

"[44][45] Others, such as conservative columnist and former Reagan speechwriter Peggy Noonan, reserved their criticism for Bush, writing: "I thought it had the sound of the rattling little aggressions of our day, but not on Mr. Webb's side.

[48] On January 3, 2007, Webb was sworn into the 110th U.S. Senate, accompanied by Sen. John Warner, R-Va., a fellow former Secretary of the Navy; and former Virginia Democratic Sen. Chuck Robb, who held the same seat before losing to Allen.

"With many of our military members serving two or three tours of duty in Iraq and Afghanistan, it is past time to enact a new veterans' education program modeled on the World War II era G.I.

In a statement on the floor of the Senate, Webb said, "The major function of this legislation is to prevent this Administration from commencing unprovoked military activities against Iran without the approval of the Congress.

[58][59] Upon his return to the U.S., Webb wrote an editorial titled "We Can't Afford to Ignore Myanmar" for The New York Times, arguing for the easing of sanctions on the country.

[64] At a United States Senate Judiciary Subcommittee on Crime and Drugs hearing, Webb described the criminal justice system as being in "... a profound, deeply corrosive crisis that we have largely been ignoring at our peril."

[69][70] Webb was frequently mentioned as a possible vice presidential Democratic nominee for Barack Obama in 2008 due to his military experience and moderate policy positions.

On November 19, 2014, Webb announced the formation of an exploratory committee in preparation for a possible bid for the Democratic Party's nomination for President of the United States in 2016.

[85] Webb's successful first novel, Fields of Fire (1978), drawn from personal experience, tells the story of a platoon of United States Marines in late 1960s Vietnam.