History can be viewed at from various perspectives, the most common of which being the names and dates method. The problem with said method is that it fails to give any insight into the causes of the various memorized events. To study history from that perspective is similar to studying biology without evolution; it becomes little more than a disparate set of fields and zoology is reduced to cataloging. To properly understand the history one needs to look at the causes of the events, and a way to do that is by studying the ebb and flow of competing ideas that are brought to a head by the issues studied in the name and date form of history. Professional historians know this, but their knowledge seldom translates down to the public school history lessons where most people are fed the simplistic version of history.
The United States was founded with two competing schools of thought, which can be exemplified by two early representatives of those schools, the Hamiltonian school and the Jeffersonian school. The Hamiltonians desire an activist government that intervenes on behalf of major industry and financial institutions, while the Jeffersonians desire a minimalist government. The signing of the Constitution was a Hamiltonian victory, but the ratification of the Bill of Rights was a Jeffersonian victory.
Early in the history of the United States, the Jeffersonians had the upper hand due to the disintegration of the Federalist Party and the ineffectiveness of the Whig party. The economic issues that divided the country were more easily reconciled by Jeffersonians who did not favor economic policies that benefited one region over another, while the interventionist Whigs had to balance competing demands from different regions of the country with different activist goals. Meanwhile several Jeffersonian presidents in a row in first the Democratic Republican Party and then the Democratic Party ensured a court that was primary Jeffersonian.
But as the economic divide in the United States grew more severe the issue of slavery became more polarized with the pro-slavery forces aligning with the Jeffersonians (even though Jeffersonians themselves aren’t pro-slavery) and the anti-slavery forces aligning with the Hamiltonians (even though Hamiltonians themselves aren’t anti-slavery). Slavery and States Rights were blocking the Hamiltonian agenda, which led to the Hamiltonians switching from the Whig Party to the Republican Party and bringing the conflict to a head in the United States Civil War.
Not all Jeffersonians were Southern. The "copperheads" were Northern Jeffersonians who objected to what they perceived to be an unconstitutional extension of Federal power enacted under Lincoln during the war. What the war did settle was which interpretation of the constitution was to dominate, the Jeffersonian version or the Hamiltonian version. Having lost the debate on the field of ideas, the Hamiltonians turned to debate on the field of battle, and there they won.
The United States was locked for a while into the Hamiltonian model, but having determined that an economically interventionist government is good the question that originally divided the Whigs arose in a new form: which model of interventionism is to be implemented? A new ideology grew in the United States after the Civil War, imported from Europe, Progressivism. These progressive initially applied themselves in the Republican Party, influencing the decisions of Theodore Roosevelt. It was the internal struggle between the Hamiltonians and the Progressives that caused the Republican Party to briefly split enabling the election of Woodrow Wilson.
During the time progressivism was trying to influence the Republican Party, it was also trying to influence the Democratic Party. The loss of the Civil War had been devastating to the efforts of Jeffersonians to limit the power of the government, and as a result the Democratic Party was open to takeover by the new ideology. This started under President Wilson but was carried to fulfillment by President Franklin Roosevelt who, while he campaigned as a Jeffersonian in 1932, acted as a full progressive once in office.
The remaining Jeffersonians, already in decline, defected from the Democratic Party to the Republican Party in response to the positions taken by the Progressives. The Hamiltonian reaction to the progressive agenda was in opposition for several reasons, including the difference between the forms of interventionism advocated, the scale of interventionism proposed by Roosevelt being beyond that of most Hamiltonians, and that Roosevelt was in the wrong party.
For a while the Hamiltonians and the Jeffersonians were uneasy allies, but did work together to try to rein in the proposals of Roosevelt and subsequent Democrat presidents, and during that time many people mistook the Republican Party as being a small government party as the Jeffersonians shaped the rhetoric while the Hamiltonians shaped the policy, but under President Nixon the strain of holding together such a coalition finally broke and a core of Jeffersonians broke away and formed the Libertarian Party.
Freed from the constraints of the Jeffersonians and no longer shocked by the scale of the progressives, the Hamiltonians finally shed their small government rhetoric and embraced a full mercantilist system under President George W. Bush of subidies for domestic industries and militarism.