Russia stopped the Germans by building more than 34000 tanks and sacrificing millions of lives. The US only really entered the war after 4 years of sitting on the side lines. Yes US support of materials to Europe was important but don’t overplay it’s significance. Also, remember that Europe paid for the US materials in gold. The US was basically acting as an arms dealer, with the 2nd world war being a huge business opportunity for US manufacturing, and the direct reason for the US moving ahead of Europe.

"West of", perhaps?

But it had beaten back most if the invasion before US materiel showed up in substantial quantity, and its industrial output (also) grew dramatically throughout the war.

Whether it could have secured enough food to sustain that output, without US SPAM, is unclear; the Soviets openly acknowledged the importance of the SPAM. The hundreds of thousands of trucks, millions of tires, millions of tons of steel, and corresponding amount of refined petrolem the US delivered probably mattered too, when it finally got there. Soviet pilots liked the P-39s, sort of proto-A10s.

The Soviet materiel placement in 1941, immediately before Germany invaded, was consistent with immediate plans to invade Germany.

Mines, lots and lots of mines.

It was a joint effort. To claim any single entity won alone is wrong. There are alternate history questions, but they will never be conclusive.

The US did almost nothing for 4 years, except selling materials to Europe in return for gold. It only joined the war after Europeans had already killed more than 23 million Germans, and destroyed most of its military. Claiming that the US won the war is BS. The US was part of a large group of countries that won the war, all contributing to defeat the Nazis.