Why was the Panama Canal not included in the miniseries "America, the Story of Us"?

In my opinion, the design, construction and operation of the Panama Canal was one of the most significant and challenging engineering projects undertaken by Americans, even more so than the Erie Canal or the Trans-continental Railroad. However, it was not included in the Mini-series "America, the Story of Us." What was the reason? Was it politics (the Canal has been turned over to the Government of Panama on January 1, 2000 and no longer belongs to the US)? It is quite perplexing to me that such an important engineering project was not included in the series. If anyone has any knowledge please answer. I am not interested in opinions that are not based on facts. Thanks.