The Line of Contact marked the farthest advance of Canadian, American, British and Soviet Armies into German controlled territory at the End of World War II in Europe. (In general "Line of Contact" refers to the demarcation between any two armies, or more, and this contact can be between belligerent or between allied armies.)
This contact began with the first meeting between Soviet and American forces at Torgau, near the Elbe river on Elbe Day, April 25, 1945. The line continued to form as American, British and Soviet forces took control of, or defeated, Nazi forces, up until the time of the May 8 unconditional surrender of Germany and beyond. This line of contact did not conform to the agreed-upon occupation zones, as stipulated in the Yalta Conference. Rather, it was simply the place where the two armies met each other. The Canadian, American and British forces had actually gone far beyond the Yalta agreement boundaries, in some cases up to two hundred miles past, going deep into the states of Mecklenburg, Saxony-Anhalt, Saxony, as well as Brandenburg. The capital of Mecklenburg, the city of Schwerin, was captured on May 2, 1945. The city of Leipzig, in Saxony, was probably the largest of the cities captured by the Americans that were inside the areas to be later passed to the Soviets. The land of Thuringia was completely occupied by American forces. The completed line of contact between Canadian/US/British forces and Soviet forces began at Wismar on the Baltic coast and proceeded south, passing along Schwerin; Magdeburg; an area east of Leipzig; and on to the Czech town of Pilsen; and towards Linz in Austria.
U.S. forces generally held onto these gains within Germany until July 1945, when under orders from President Harry S. Truman, and against the advice of British Prime Minister Winston Churchill the U.S. forces withdrew to the Yalta agreement boundaries dividing Germany into occupation zones. It is worth noting that the Soviet Union may not have allowed American and British forces into Berlin, which was completely under their control, if the U.S. had not honored the Yalta agreement boundaries. The German areas relinquished by American troops became part of the Soviet-dominated East Germany.
The US Army did not withdraw from western Czechoslovakia until December 1945, as part of an agreement removing all American and Soviet troops from the country. US, British and Soviet controlled territory in Austria was incorporated into an occupation plan. Along with a created French zone, Austria remained technically an occupied country by the Four Powers until 1955, when all foreign troops departed. Austria managed to stay free of Soviet domination, whereas Czechoslovakia did not.