Simplify the following text for a Grade 5 native English-speaking person.
Original: John Calvin Coolidge ( July 4 , 1872 - January 5 , 1933 ) was the 30th President of the United States between 1923 to 1929 .
Simplified: John Calvin Coolidge , Jr. , ( July 4 , 1872 - January 5 , 1933 ) was the 30th President of the United States ( 1923 -- 1929 ) .