Of course, what often goes unsaid is that things have changed significantly since the time of Lincoln, and those changes have to be understood in their larger historical context. All too often, unfortunately, we tend to get distracted by demagogues, by the latest political and ideological fashions, by the prejudices of 'common sense,' etc., and we lose sight, as a consequence, of the need to educate ourselves on the historical evolution of the many factors that have contributed to the problems we face today.
Complex and entrenched problems are not amenable to simplistic solutions. They require for their solution, at the very least, a recognition and correct diagnosis and understanding of their historical, sociological and philosophical context. But we must know the context. In that spirit, and although I highly recommend you pick up some history books, here is a short animated introduction to how the Party of Lincoln eventually became the Party of Trump.
Of course, the Democratic Party has undergone an evolution of its own, starting as the party of white supremacy, and eventually becoming the party that would elect the first African-American president:
Go home, America! You're drunk. :p