Rothko likened his abstract work to a mystical experience.
"The fact that a lot of people break down and cry when confronted with my pictures shows that I can communicate those basic human emotions ... The people who weep before my pictures are having the same religious experience I had when I painted them."
Rothko's work may at first seem "random", but it was carefully thought through.
He wanted viewers to stand close to his paintings, and let themselves be absorbed and overwhelmed by them.
Colours were carefully placed together to create a special resonance and vibration.
The paintings are meant to "expand and push outward in all directions...or inward in all directions".
Rothko is considered one of America's most influential artists.
One of his paintings recently sold for $86 million.