Short answers, pulled from the story.
President Abraham Lincoln signed a bill authorizing two hundred medals of honor for naval personnel on the 21st of December 1861. This legislation emerged from a proposal by Lieutenant Colonel Edward D. Townsend to Lieutenant General Winfield Scott.
Private Jacob Parrott became the first actual Medal of Honor recipient when awarded for participation in a raid on a Confederate train in Big Shanty, Georgia on the 12th of April 1862. Six decorated soldiers met President Lincoln in the White House after presentations.
Public Law 88-77 passed on the 25th of July 1963 standardized requirements across all services requiring recipients to distinguish themselves conspicuously by gallantry and intrepidity at risk of life above and beyond call of duty. Congress drew three circumstances of combat from President Kennedy's executive order of the 25th of April 1962 including engagement against enemies or military operations involving conflict with opposing foreign forces.
Each recipient's name enters Medal of Honor Roll certified to Department of Veterans Affairs for monthly pension above any other military pensions. Current pension amount stands at $1,671.16 per month subject to cost-of-living increases.
Mary Edwards Walker remains sole woman recipient despite receiving her award in 1865 while serving as civilian Army acting assistant surgeon. Her case later led to revocation in 1917 before questionable reinstatement by Army Board in 1977.