1896 -- "Cross of Gold" by William Jennings Bryan 
Just before the turn of the 20th century, Nebraska Congressman William Jennings Bryan arrived at the Democratic convention as an underdog candidate and left it as the party's champion. Bryan made a roaring speech on behalf of Blue Collar America, claiming that it would suffer if Washington decided to base its economy on the gold standard.

"You shall not press down upon the brow of labor this crown of thorns," Bryan bellowed at the end of his speech. "You shall not crucify mankind upon a cross of gold!" There was a moment of silence …then the entire convention went nuclear. Bryan became an overnight hit amongst Democrats and easily earned the nomination easily, but lost the election to William McKinley.

1932 -- "The New Deal" by Franklin Delano Roosevelt
Once upon a time, candidates would remain silent until the delegates confirmed them as the nominee. FDR turned that on its head by announcing beforehand that he would be making an acceptance speech, one that came to define his legacy as he promised a "new deal for America" while the nation struggled with the Great Depression.

1960 -- "The New Frontier" by John F. Kennedy
JFK's acceptance speech was based on a simple idea: America's only hope for progress was to put all its focus on the future, even if it had to drag its more nostalgic side along with it. "It would be easier to shrink from that new frontier, to look to the safe mediocrity of the past, to be lulled by good intentions and high rhetoric," Kennedy mused during his acceptance speech, "and those who prefer that course should not vote for me or the Democratic Party."

1964 -- "In Defense of Liberty" by Barry Goldwater
If JFK's speech was a call to boldly face the new, Barry Goldwater's Republican Convention speech four years later was a call to arms in defense of the old. Goldwater and his supporters doubled-down on an anti-Civil Rights platform, with Goldwater declaring that "extremism in defense of liberty is no vice" and "moderation in the pursuit of justice is no virtue."

1976 -- "No Pastel Shades" by Ronald Reagan
Though Goldwater's policies were roundly rejected by the electorate, future Republicans would adopt his "stand your ground" mentality when it came to conservative principles to great success. Take Reagan's '76 concession speech, which paved the way for his 1980 victory when he called on Republicans to commit themselves to a platform "that is a banner of bold, unmistakable colors, with no pastel shades."

1980 -- "Dream Shall Never Die" by Ted Kennedy
There may never be a greater concession speech than this. Despite not having enough delegates to win, Sen. Ted Kennedy made a last ditch attempt to wrestle the nomination from Pres. Jimmy Carter. Upon failure, Kennedy assured his fellow Dems that "the work goes on, the cause, endure, the hope still lives, and the dream shall never die." When Carter failed to move the needle in a similar way, it became a sign that the splintered Democrats were not going to be able to challenge Reagan.

1984 -- "Reagan's City" by Mario Cuomo
Four years later, the Democrats were still struggling to find their voice again as Reagan continued to redefine conservatism. Enter N.Y. Governor Mario Cuomo, who gave a keynote speech that solidified the liberal opposition to Reagan by challenging his vision of America as a city on a hill.

"A shining city is perhaps all the President sees from the portico of the White House," Cuomo said. "But there's another city … In this part of the city there are more poor than ever, more families in trouble, more and more people who need help but can't find it ... There is despair, Mr. President, in the faces that you don't see, in the places that you don't visit in your shining city."

1988 -- "Read My Lips" by George Bush
Much like how "The New Deal" became the phrase that defined FDR's pre-WWII presidency, George Bush's one-term presidency was judged by how he committed himself to the famous six-word declaration he made at the '88 RNC: "Read my lips: No new taxes." 

2004 -- "One America" by Barack Obama
Back when he was a junior senator from Illinois, Barack Obama began his road to the White House with a rousing call for unity as the keynote speaker John Kerry's '04 DNC. Obama called out "the negative ad peddlers who embrace the politics of 'anything goes'" and declared that "there is not a liberal America and a conservative America … there is the United States of America." Overnight, Obama became nationally known as a bold, youthful uniter.