When world war II ended in 1945 parts for more 100 V-2 missiles were shipped from Germany to USA. Along with the rocket parts, Wernher von Braun, Walter Dornberger and 124 other scientists and technicians from the V-2 production, were in American hands.
White Sands Proving Ground. in New Mexico became the center of the US experiments with the V-2. Since the rockets were launched without warheads, there were plenty of space for scientific use of the rockets. So the V-2 ended up as a sounding rocket.
V-2 no. 3 was launched on May 10, 1946 and were the second V-2 launched from White Sands (No. 1 was only used for a static test).
Like the first V-2 launched by von Braun in Germany, the rocket was decorated with a pin-up girl.
The V-2 carried different scientific instruments. The flight was a success, but the scientific payload was more or less destroyed at the impact with the ground. The V-2 were after all not designed as a sounding rocket.
Later the scientist managed way to recover the data from the experiments, and about 70 V-2's were launched in the US. The last one launched 19 September, 1952
Books and other sources:
Rockets of the world by Peter Alway,
V-2 Ballistic Missile 1942-1952 by Steven J. Zagola
Dawn of the Rocket Age by Joachim Engelmann
The Rocket - The History and Development of Rocket and Missile Technology by David Baker.
Begg's Aerospace (Highly recommended)