The document outlines four major eras of the two-party system in American history:
1. The Era of the Democrats from 1800-1860 which saw the Democratic party dominate until the Civil War.
2. The Era of the Republicans from 1860-1932 where the Republican party gained control after the Civil War and held the presidency for 75 years.
3. The Return of the Democrats from 1932-1968 when Franklin Roosevelt was elected amid the Great Depression and the Democratic party regained power until the 1960s.
4. The Modern Era from 1968-present with a more divided government and the parties alternating control of the presidency.