Sources

https://www.informationisbeautiful.net/visualizations/left-vs-right-us/

https://www.pbs.org/wgbh/americanexperience/features/lincolns-timeline/

https://inthesetimes.com/article/politics-party-system-america-democrats-republicans

https://www.diffen.com/difference/Left_Wing_vs_Right_Wing

https://news.gallup.com/poll/275792/remained-center-right-ideologically-2019.aspx

https://www.pewresearch.org/politics/2014/06/12/political-polarization-in-the-american-public/