How it fits together
The United States entered World War I in 1917. Attacks on shipping were among the reasons. The Great Depression began in 1929 and brought severe economic hardship. Franklin D. Roosevelt became president in 1933, during the Depression, and later led the country during much of World War II.
A closer look
Japan attacked Pearl Harbor on December 7, 1941; the United States declared war on Japan the next day. Do not merge the two world wars into one story. Roosevelt and Eisenhower also had different roles during World War II: Roosevelt was president, while Eisenhower was a senior military commander.