I would say that the dispatching of a US expeditionary force to ensure the victory of the Whites in 1918 during the height of the Russian Civil War had a lot to do with it.

The US didn't recognize the Soviet Union officially until 1933, and always saw it primarily as a threat to the stability of countries with extensive links to the US economy.

Relations weren't great from the Bolshevik Revolution through World War II, but we tolerated them. Most of the anti-Russian feelings came about with the decisions made after the war. Russia wanted Germany to pay heavy reparations, while the remaining Allies wanted to simply rebuild Europe and avoid conflict. Stalin was paranoid the United States was trying to screw him over (to an extent he was correct), which also contributed to the fallout in relations. The biggest point we as historians can point to and say when relations really got bad was in the aftermath of the Potsdam Conference where Stalin openly accused Truman of "trying to keep Russia weak." The United States and Soviet Union weren't really on speaking terms after that...

I'd imagine it's got something to do with nationalization of property. I know that "we hated communism" but beyond that I'm at a loss.