Complex sentence: In the late 1960s Nation had attempted to launch the Daleks as a series in their own right in the United States, and although his attempts were unsuccessful, he did find himself increasingly working in that country and eventually moved there.
Split into simpler sentences: In the late 1960s Nation attempted to launch the Daleks as a series in their own right in the United States. Although his attempts were unsuccessful, he did find himself increasingly working in that country and eventually moved there.