Complex sentence: In June 1939, Elizabeth and her husband toured Canada from coast to coast and back, and visited the United States, spending time with President Roosevelt at the White House and his Hudson Valley estate.
Split into simpler sentences: In June 1939, Elizabeth and her husband toured North America. The tour took them across Canada from coast to coast and back, and into the United States, where they visited the Roosevelts in the White House and at their Hudson Valley estate.