Article II, Section 2, of the Constitution provides that the President shall appoint officers of the United States “by and with the Advice and Consent of the Senate.”

Article II, Section 2, of the Constitution provides
that the President shall appoint officers of the
United States “by and with the Advice and Consent of the Senate.”

https://www.fas.org/sgp/crs/misc/RL31980.pdf

http://www.senate.gov/CRSpubs/be873e40-a966-4feb-9d72-cf23a93cbe46.pdf

Electoral College:

https://www.archives.gov/federal-register/electoral-college/key-dates.html