This is a good question, I thought I had answered this before
but it looks like I never did.
Anime wasn't always considered Anime, it was Japanese
Animation or Japanimation until in the mid-to-late 90s. The term
"anime" is essentially the shortened version of it all so
techncially anything that is animated, even CGI movies are
considered anime, yes even Shrek.
With that said, american cartoons are also considered anime in
Japan. From a Japanese point-of-view, any animation is considered
Anime and therefore cartoons are anime. However, this is not to say
that in the US or outside of Japan this isn't the case. Anime is
generally referred to as Japanese animation and not just any kind
of cartoon or animation.
Where am I going with this you may ask? It's to answer your
question because there are two types of Anime. The anime you hear
people talk about in Japan and the anime the non-Japanese talk
about. The very first anime happened in 1917 but wasn't called
"anime" at the time. I wrote an article decribing how anime
actually comes from a french manga artist but basically it did in
the 1970s. The term gained momentum especially in the 80s. In the
90s that's when it became very mainstream and in the mid-to-late
90s it was all over the world.
Unfortunately there was an anime crash in the 90s but the
industry bounced back. It might actually happen again but we will
see if it does or doesn't.
I'm not sure in which article the details of this information
is in and it may have been hidden at some point. Here's a list of
articles that may be helpful:
https://www.jappleng.com/education/course/overview/4/japanese-culture