My first reddit rant, excuse shitty formatting...
https://en.wikipedia.org/wiki/Party_divisions_of_United_States_Congresses
https://en.wikipedia.org/wiki/George_Washington%27s_Farewell_Address#Political_parties
If you mean 'relatively recent' as in immediately after the inauguration of George Washington... The representatives were split among many things, but primarily the introduction of the bill of rights.
Other issues included whether or not we should create a standing army or honor the defensive treaty signed with France during the Revolutionary War. Washington's famous Farewell Address comes from within this context. That address famously warns of the dangers of political factions, but that doesn't appear out of a vacuum... Jefferson and Adams had just founded the DR and the Federalist parties, respectively.
https://en.wikipedia.org/wiki/United_States_presidential_election,_1860
https://en.wikipedia.org/wiki/United_States_presidential_election,_1876 (This is the second election after the war with all states participating)
There was briefly a four party alignment in American history, caused by the two major parties sieving sections of their parties due to internal disagreements specifically about the slavery question. This was resolved almost immediately.
https://en.wikipedia.org/wiki/Voter_turnout_in_the_United_States_presidential_elections
https://en.wikipedia.org/wiki/Voting_rights_in_the_United_States#Young_people
Turnout has dropped a little over time. Most notably at the end of the gilded age.
Numbers were likely inflated in the gilded age, as political organizations such as Tammany Hall stuffed ballot boxes (among other things).
Voting eligibility =/= the opportunity to cast a ballot. Women recently won the right to vote, so all women would be counted as voting age population, but that doesn't mean that they had the cultural (or literal) opportunity to cast a ballot. This is also a factor for the decline after the sixties as people of color no longer had to deal with the myriad of laws restricting voting eligibility (yet, they still deal with societal and cultural impedances to casting a ballot).
After that point, it looks like there is a 10% decline in overall turnout over the last 40 years. Part of this, I think, had to do with the 26th amendment, as 18-20 year old people are a more mobile population and less likely to find value in participating, or even be able to find where to vote/register because (prior to the internet) it was difficult to learn where to go in new cities/environments. You do see total turnout increasing in the last 10 years, likely because the internet negates every reason I mentioned regarding young people not participating.
Bonus Section: https://en.wikipedia.org/wiki/Propaganda_of_the_Spanish%E2%80%93American_War
http://www.cnn.com/2008/LIVING/wayoflife/08/22/mf.campaign.slurs.slogans/index.html?_s=PM:LIVING
My Favorite Quote: Jefferson's camp accused President Adams of having a "hideous hermaphroditical character, which has neither the force and firmness of a man, nor the gentleness and sensibility of a woman."
In return, Adams' men called Vice President Jefferson "a mean-spirited, low-lived fellow, the son of a half-breed Indian squaw, sired by a Virginia mulatto father."
Slander and misleading information masquerading as fact are nothing new. The only difference is you are alive to witness the current mess (which is good and exciting thing! It's why I love history so much.)
Sorry for the wall of text, but my spidey sense was tingling as a professional armchair historian and holder of a US history specialization.