Final answer:
The Democratic Party dominated American politics from 1828 to the mid-1850s and again during the 1930s, with Franklin D. Roosevelt's New Deal coalition. Outside of these periods, the party struggled on a national level, particularly between 1868 and 1931.
Step-by-step explanation:
The Democratic Party has had periods of dominance in American history, specifically from Andrew Jackson's presidency in 1828 until the mid-1850s, a time known for personal politics. Another significant period of dominance was during the 1930s under Franklin D. Roosevelt, forming a coalition that included multiple diverse groups. However, from 1868 to 1931, Democrats struggled nationally, winning only four of sixteen presidential elections. The dominance shifted as the party's stance on social issues, particularly civil rights, evolved.
Furthermore, early American history saw the decline of Federalism, with the Democratic-Republicans, forerunners to the Democrats, achieving ascendancy with Thomas Jefferson's election in 1800. The Democrats' influence waxed and waned, with a notable decline post-Civil War due to opposition to civil rights, up until they embraced a broader coalition under FDR. This legacy points toward the complex interplay of social issues and political power in defining party dominance in the Federal Government.