Why are Thomas Jefferson and Samuel Adams significant in American history?

Both are founding fathers which is already significant in tying them to american history, but most importantly both helped established the culture of the US, whether that be unalienable rights or the promise of freedom to all men.

Note:

These two men have a long list of achievements that make them significant in american history. I only listed a two.

might be agreeing to participate ethically with other european nations in the slave trade

or notifying other european nations when taking possession   of african territories

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.