Eisenhower could have taken Berlin, but he chose not to. Big mistake.
Massive military aid no doubt helped, but had zero boots on the ground on the eastern front. Germany was, without doubt, defeated by the Soviet Union. Germany tendered its surrender to the Soviets in May and the American army did not get to Berlin until July, more than a month and a half later.
Eisenhower could have taken Berlin, but he chose not to. Big mistake.
Eisenhower couldn't take Berlin before the Soviets had already done so. At any rate, it is historical fact that the Americans did not do so.
https://en.wikipedia.org/wiki/Eastern_Front_(World_War_II)
The Eastern Front was a theatre of World War II fought between the European Axis powers and Allies, including the Soviet Union (USSR) and Poland. It encompassed Central Europe, Eastern Europe, Northeast Europe (Baltics), and Southeast Europe (Balkans), and lasted from 22 June 1941 to 9 May 1945. Of the estimated 70–85 million deaths attributed to World War II, around 30 million occurred on the Eastern Front, including 9 million children. The Eastern Front was decisive in determining the outcome in the European theatre of operations in World War II, eventually serving as the main reason for the defeat of Nazi Germany and the Axis nations. It is noted by historian Geoffrey Roberts that "More than 80 percent of all combat during the Second World War took place on the Eastern Front".
The Russians were fighting with Germany in June 1941. D-Day did not happen for the American army until 1944. The U.S. was fighting the war in the Pacific.