"The American lend and lease system was introduced in the beginning of the war to support Great Britain in their struggle with Germany. After the German assault on Russia in June 1941, the defenders got aid with this system through war material, food, fuel and other important raw materials.
From 1941 and onwards, the RKKA used extensive numbers of Lend-Lease tanks received from the USA, CANADA and GREAT BRITAIN. Approximately 22.800 AFVs were sent to the Soviet Union between June 22nd of 1941 to 30th of April 1944, and almost 2.000 of these were lost at sea. In addition, the Russians got about 351.700 trucks and 78.000 Jeeps from the USA. With this the Red Army became more movable as mobility increased.
During 1941, 487 Matilda, Valentine and Tetrarch tanks were received from Great Britain, and 182 M3A1 "Stuart", and M3 Lee medium tanks were received from the USA. In 1942, a further 2.487 tanks were received from the UK, and 3.023 tanks from the USA. The first units equipped with Valentines and Matilda IIs fought in the Staraya Russia and Valdai areas in the winter of 1941/42. Usually tank units were allotted a single type of Lend-Lease tanks to simplify logistics. An example was the 38th Tank Brigade which in 1942 had 30 Matilda II tanks, and 16 T-60 light tanks. In 1944 and 1945, the American M4A2 were the highest appreciated Lend/Lease tank, and some tank corps and mechanized corps were entirely equipped with this type. In early 1945 the 1st Guards Mechanized Corps were equipped with Shermans in all of its tank units. The role of Lend/Lease AFVs in the Soviet war effort has been the source of bitter controversy, as some Western statements tell how decisive they were, while Soviet statements generally denigrating it as inconsequential. However, it should not be forgotten that Great Britain sent 14 percent of her's total tank production to the Soviet Union, even though they outproduced Great Britain threefold in tanks, and this in a period when the British Army had a serious shortage of tanks in North Africa. The vast quantities of American trucks with USA serials provided, were so common in Eastern Europe in 1944/45, that common folk-lore interpreted the stenciled letters as Ubiyat Sukinsyna Adolfa - Kill that Son-of-a-bitch Adolf."
Taken from --
http://www.skalman.nu/soviet/ww2-lendlease.htm
As you can see, it was not only America which gave things to the USSR, other countries did too (CANADA, UK). UK even gave 14% of all its tanks to the USSR, when they themselves were in a bad possition and short on tanks, quite a sacriface.
The truth is not "without the US, Germany would have won." The truth is without all of these countries coming together to fight a common foe, Germany would have won.
I give credit to the US for helping to win the war, I do NOT give credit to the US for winning the war.
"Just remember the debacle at Dieppe. An invasion by Canadians and British, that failed. With the US, they succeed."
Dieppe provided the base from which the D-day plan could be modeled. And without the the lessons learned at Dieppe, the losses to troops on D-day would have been much higher.