It all actually started with the Articles of Confederation, way back in 1770's, which made a mention of how the federal government was to operate. Thus began the journey of the USA's federalism and it became the first modern national federation in the world in the 18th century. The federal system or federalism primarily is a style of functioning of the government where the political power and the power of governance is shared between the political units and a central governing authority. That is termed as federation. The government of USA too has been formed in the same way. Federalism in the United States, at the core level, is explained as the changing and developing relationship between the states and the federal government of the USA. The text to follow will elaborate on this more. Federal System in the USA As mentioned earlier, the federal system in United States is constantly undergoing change and evolution since the time it was introduced in the constitution. It is impossible to cover all the nuances of this huge political and constitutional legacy, but I will try and describe the landmarks in the development of federalism in American history. The Early Days The Articles of Confederation were responsible for that first spark of discontent amongst the states against the federal government. These were, in fact, focused on limiting the power of the federal government in 1790's, albeit without a lot of impact. There was a lot of discontent as the Federal government proved to be unable to handle a rebellion of farmers in Massachusetts as a result of poor economical machinery. In 1787, the foundation for a bicameral legislature and a construction of a new US Constitution was decided in Philadelphia. Those who opposed the new constitution were the anti-federalists. In 1789, Congress submitted twelve articles of amendment to the states, of which ten of these articles, written by Madison, got passed on December 15, 1791. These became what was to be known as the Bill of Rights. In that, the Tenth Amendment put forth the guidelines for federalism in the United States. Eventually this division of federalist and anti-federalist movement got exhausted. The Era of Marshall and Taney and Dual Federalism In the period of early 18th century, Chief Justice John Marshall had a major role to play for defining the power allotted for the federal government and the state governments. The reason was that federalism was not yet clearly described in the United States constitution. Hence the onus was on the Supreme Court to sort out matters of power and decision-making, and the federal system between the two. A few cases specifically widened the expanse of the federal government's power. Roger B Taney, Marshall's successor, gave verdicts which favored the federal government as well as the state governments equally. The seeds of Dual Federalism in the United States were thus sown there. Dual Federalism primarily meant that the federal government should stick to the enumerated powers and not go beyond them. The other functions and powers should be left to the state governments. However, the sixteenth and the seventeenth amendment bolstered the federal government's powers. Dual Federalism was in practice for almost a century following Taney and Marshall. Later in this period, the demarcation became even more steep, with local governments apart from state governments added to the governmental machinery. While the federal government was allotted subjects like Centralized National Defense, Foreign policy, Copyrights, Currency Patents, state governments were allotted subjects like Civil Service Laws, Property Law, Labor and Union Laws and the like. Finally, local governments were supposed to handle issues like Assessable Improvements and Basic Public Services. This was a huge shift in the federalism in the United States. You can also go through Articles of Confederation vs Constitution for more information on constitution of the USA. Great Depression and Abrupt Change Dramatically enough, as a result of the Great Depression, the balance of power shifted to the federal government back again because of the downfall of US economy. The New Deal policies by Franklin Roosevelt seemed to have caught the pulse of the American citizens. The New Deal fundamentally compelled the federal government to cooperate with the other levels of government for the implementation of the policies under it. This was time when it was called Cooperative Federalism, where federal funds were distributed by way of grants in aid or categorical grants. These gave the federal government better control over the usage of money. Eventually, it was time for 'New Federalism' in the United States. This is a comparatively recent phenomena, having come up in the early 20th century and early 21st century. The pioneer of this shift in the balance of power from the center to the states was pioneered by president Ronald Reagan - (1981-1989). It was then called devolution evolution. Some of the presidents till Bill Clinton embraced this philosophy. The main objective of this shift in ideology was to restore some of the lost autonomy and power to the states a result of the New Deal. This was a brief account of federalism in the United States - how the power shifted and the pendulum of power swung sometimes in the favor of the federal government and sometimes in support of the states. This struggle for power and autonomy, although stabilized right now, can again be visible, as has been the legacy, whoever the president may be.