>>98249200Long story short:
Anime was obscenely popular in the US from the late 90's up until about 2007. At its peak more than 20 US television channels had a dedicated anime block, you could by manga in airport shopping kiosks, etc etc.
In late 2007, the economy imploded, CN got new managements, and illegal downloading and streaming services became viable to the general public. Late 2007-2008 marked a sudden decline in US interest in anime, which only really began to recover in the last 3-5 years.