Who was the 3rd party candidate that earned a significant number of popular votes?

In the 1912 U.S. Presidential elections, former President Teddy Roosevelt emerged as the most successful third party presidential candidate in the history of the country when he bagged 88 Electoral votes and 27% of the popular vote in the election on behalf of the Progressive Party of the United States. The party was formed by Roosevelt himself when he failed to receive the nomination from the Republican Party in the 1912 Elections. However, Roosevelt lost, and the election was won by the Democratic Party's nominee, Woodrow Wilson, who went on to become the 28th President of the United States. The 1912 Presidential elections were unique in the fact that this was the last election where a candidate who was neither Republican nor Democrat came second in the election. This occurred as Teddy Roosevelt defeated Republican William Howard Taft and Socialist Eugene Debs.

since most of current immigration into the u.s., both legal and illegal, is coming from latin america. it would be very difficult to imagine or rationalize a country my fellow citizens are trying desperately to flee into, would pose a threat to my prosperity or freedom. since the u.s. has a long history of intervention, but no record of permanent occupation, i would not feel oppression is the main objective.  

the largest free trade nation, along with the largest gdp in the world wanting to expand it's economic policy on us, and including us, could only be positive. the u.s. government has no interest in, or way of simply forcing american culture on us. and has no track record of it. other nations that adopted american social culture, or "americanization" did so voluntarily, mainly through the choice of allowing american businesses and u.s. citizens to come into their nations, as free operatives.