Fifty years ago, at the NDP's founding convention, Tommy Douglas said he believed the newly-formed party would one day form the government of Canada.

It's not quite there, but the NDP is as close as it's ever been, following an election campaign that saw it achieve Official Opposition status on May 2.

The party has come a long way from that convention in 1961, and has seen its share of ups and downs.

The New Democratic Party was born through the unification of the Co-operative Commonwealth Federation and the Canadian Labour Congress. Douglas, the legendary political figure best known as the architect of Canadian medicare, was its first leader.

He was chosen at that historic 1961 convention in Ottawa over Hazen Argue, a fellow politician from Saskatchewan. Argue, who had been a CCF MP, ditched the NDP after he lost the leadership to Douglas by more than 1,000 votes. He joined the Liberal Party and was later made a senator.

"This is not the time to argue, you'll pardon me using that word," Douglas said during his pitch to convention delegates, drawing a laugh from the crowd. "This is not the time to argue about right wings or left wings. This is the time to unite all our forces for the task which lies before us — the task of creating a society which will make the wealth production of Canada available to all who labour with hand and brain."

Douglas went on to talk about leadership and the importance of unity within a party in order for it to achieve success.

David Lewis succeeded Douglas as leader, serving from 1971 until 1975. Ed Broadbent then took over and was leader for more than a decade until 1989.

Audrey McLaughlin became the first woman to lead a major federal party in Canada when she succeeded Broadbent. She was followed by Alexa McDonough.

Layton beat out a number of candidates, including sitting MPs, to replace McDonough in 2003. He wasn’t a Parliament Hill player at that time, but won a seat in the House of Commons a year later in Toronto-Danforth.

Quebec's key role

Layton led his party to its best showing ever in the 2011 election, shattering the party's previous records and bumping the Liberals out of the Official Opposition. The NDP jumped from 37 to 103 seats, an electoral success largely due to an "orange wave" that swept through Quebec. The party went from one to 59 seats in the province.

Jack Layton, left, led the party to its best showing in 2011, achieving a breakthrough that eluded Ed Broadbent in the 1980s. Canadian Press A breakthrough in Quebec is what eluded Broadbent and was the reason he resigned as leader, he told CBC News in an interview in June.

"The wind went out of my sails personally, I really saw that as a big setback," he said. "I left over Quebec, essentially, in 1988 — we didn't get the breakthrough."

Broadbent describes the historic election result in May as a "glorious moment" and while the party is now far different in its composition than when Broadbent was in the caucus, he said it hasn't strayed from its roots.

"I don't think the party has changed ... the issues have changed," Broadbent said, explaining that the party adapts to issues that are current at the time.

Back in the 1970s and '80s, feminism was a big issue, he said as an example, whereas now Canadians are concerned with health care and pension security.

"I don't think there's a shred of evidence that would say it's changed its core values of equality, liberty, solidarity, what it believes in," he said.

Broadbent and Layton both enjoyed high public opinion approval ratings, but their personal popularity hasn't always translated into success for the party. Until now, the NDP had been stuck in the corners of the House of Commons, never on the government or Opposition benches.

Layton, a Toronto city councillor before he came on the federal scene, was determined to change that. He steadily grew the NDP's vote share in every federal election he fought. He won the keys to Stornoway, the residence for the Official Opposition leader, and said he was gunning for 24 Sussex Dr., where Prime Minister Stephen Harper now lives.

NDP's ups and downs

The party hasn't always enjoyed such jubilant times.

In the early 1970s it faced a crisis of division when a subgroup formed within the party, called the Waffle Group. It called for the protection of national unions as opposed to international ones and mounted a campaign for less corporate American ownership in Canada. It threatened to disrupt the party's momentum and in 1972, it was disbanded.

In 1993, McLaughlin failed to keep the party's seat count in the double digits and the NDP dropped to just nine seats after the 1993 election.

McLaughlin passed the torch to McDonough, who began to rebuild the party from that setback, and slowly but surely it gained ground again.

Though the NDP had been the fourth party in the House of Commons for a decade, its members say they have been able to wield great influence. They often point to the deal Layton struck with then-Liberal prime minister Paul Martin in 2005 as an example. Layton supported the minority Liberal government in a crucial budget vote in exchange for amendments to the budget.

The following year, he helped bring Martin's government down when the NDP supported a motion of non-confidence moved by Harper and the Conservatives.

The NDP has worked hard over the last several years to widen its appeal to Canadians and to edge out the Liberals as the main alternative party to the governing Conservatives.

It has celebrated isolated victories along the way, such as when current Deputy Leader Thomas Mulcair stole Montreal's Outremont seat away from the Liberals. The party had cause for celebration again when Linda Duncan captured the only non-Conservative seat in Alberta in 2008. She was just the second NDP MP to ever be elected in the Tory stronghold province.

Brad Lavigne, the party's former national director who left that job after the election to become Layton's right-hand man, says the NDP's founding members would be proud of how far the party has come.

"If you take a look at the architects of our founding back in 1961, they spoke about the day where we'd be in a position to be the government-in-waiting," he said this past spring.

May 2, 2011 ended up being that day.