Influence by American designs on the T-34?

The Christie tanks, which were copied and developed as the BT-series, is an obvious example as they were the forerunners of the T-34.

Another example which has a strong resemblance to the T-34 is the Medium Tank T4. This was built by the Rock Island Arsenal. I don't know if Christie was involved in it's design, but it definitely draws heavily on some of his ideas.