Complex sentence: Julie Nixon was born while her father, Richard Nixon, was a Congressman; but much of her childhood coincided with her father's service as Dwight Eisenhower's Vice-President (1953--61).
Split into simpler sentences: Julie Nixon was born while her father, Richard Nixon, was a Congressman. Much of her childhood coincided with her father's service as Dwight Eisenhower's Vice-President (1953--61).