The very first successful anime in America was
Astro Boy (Americanization of
Tetsuwan Atom) in 1963.
After that,
Gigantor (Americanization of
Tetsujin 28-goh) in 1966.
After that,
Speed Racer (Americanization of
Mach GoGoGo) in 1967.
Then,
Battle of the Planets (Americanization of
Gatchaman) in 1972.
Then,
Star Blazers (Americanization of
Cosmoship Yamato aka
Space Battleship Yamato) in 1979.
Then,
Voltron (Americanization of
Beast King Go Lion) in 1984.
Then,
Robotech (Americanized mashup of
Macross and two other anime) in 1985.
It's probably true most of the people who watched these didn't realize they were originally Japanese cartoons, though, and they didn't have much lasting impact; these shows would get buzz for a little while, and then fade away.
The mid-late 1990s was indeed the start of the anime boom in America, with the back-to-back successes of
Dragon Ball Z,
Sailor Moon,
Pokemon,
Digimon,
Ronin Warriors (Americanization of
Samurai Troopers), etc. This was the first time viewers were conscious of the fact they were watching imported cartoons from Japan, and interest continued to grow from there.
Still, the medium as a whole didn't became "mainstream" in the 1990s. That was when anime first
started to become mainstream, sure, but it was really just a couple of shows that were popular. I would say anime only became mainstream in the streaming era during the 2010s. During the era of appointment TV, not really.
Even now, you can argue anime still isn't exactly "mainstream", because it's considered geeky. Cartoons, comics, videogames, etc; popular as they all are, having more than a casual interest in them is gonna get you labeled as a nerd.
Anyway,
@DBZAOTA482 the way you repeatedly shill
Dragon Ball and treat it like the most iconic or influential anime/manga series ever made is tiresome. At the end of the day, you're biased when you're looking at things exclusively through a Western perspective. Plenty of other mangaka had to walk so Toriyama could run. Who cares which series triggered the boom or whatever in America? Much of DBZ's success in the country came down to luck (barely any anime were widely broadcast in the US before DBZ in 1996).
At the end of the day,
Demon Slayer's success blows
Dragon Ball's out of the water. It's grossed almost the same amount of money ($10 billion plus) in just 10 years.