Short answers, pulled from the story.
Sega's Heavyweight Champ, released in arcades in 1976, is considered the first video game with fist fighting, though it was still classified as a sports game. Karate Champ, released by Data East in May 1984, is credited with establishing the one-on-one fighting game genre as a distinct category.
Street Fighter II, released in 1991, standardized the genre by allowing players to fight each other rather than only computer-controlled opponents. Its accurate joystick scanning routine let players reliably execute special moves, and it popularized the combo mechanic, which players discovered by chaining attacks that left no time for opponents to recover.
Evo Moment 37, also called the Daigo Parry, occurred at Evolution Championship Series 2004 during a Street Fighter III: 3rd Strike semi-final. Daigo Umehara, with only one pixel of health remaining, parried 15 consecutive hits of Justin Wong's Chun-Li Super Art move and won the match. It is frequently described as the most iconic moment in competitive video gaming history.
Super Smash Bros. Ultimate, released for the Nintendo Switch in 2018, is the best-selling fighting game of all time with 37.76 million copies sold worldwide. It features nearly 90 characters through its default roster and downloadable content.
Street Fighter is the highest-grossing fighting game franchise, with total gross revenue of $10.6 billion from arcade, console, and computer games as of 2020. The franchise was created by Takashi Nishiyama and Hiroshi Matsumoto and is owned by Capcom.
Multiple developers attributed the early 2000s decline to increasing complexity and over-saturation, which pushed casual players out of the market. The simultaneous decline of arcades, as home consoles grew more powerful and popular, removed the social venues where fighting game communities had formed throughout the 1990s.