While both India and the United States operate under a federal system, there are fundamental differences in their structure and operational dynamics. These distinctions reflect their historical contexts, constitutional philosophies, and political evolutions.

One primary difference lies in the nature of the federation. The US is a 'true' federation, formed by an agreement among independent states that voluntarily came together, granting limited powers to the federal government while retaining significant autonomy. India, on the other hand, is often described as a 'quasi-federal' system with a strong unitary bias. It is a 'Union of States' where states did not come together by agreement and have no right to secede. The Indian federation was created by the division of powers within a pre-existing unitary state.

Citizenship is another key differentiator. The US has a system of dual citizenship, where individuals are citizens of both the United States and the state in which they reside. India, in contrast, adopts a single citizenship, meaning all citizens owe allegiance only to the Union of India, fostering national unity.

The division of powers also varies significantly. In the US, the federal government has enumerated powers, and all residuary powers (powers not explicitly assigned) rest with the states. In India, while powers are divided into Union, State, and Concurrent Lists, the residuary powers are vested with the Union Parliament, indicating a stronger central government.

Furthermore, the Indian Constitution is more flexible and detailed compared to the relatively rigid and brief US Constitution. India also has an integrated judiciary with the Supreme Court at the apex, while the US has a dual judicial system with separate federal and state courts. India's emergency provisions grant the central government extensive powers to transform the federal structure into a unitary one during crises, a feature largely absent in the US system. The appointment of state governors by the President in India, as opposed to elected state governors in the US, further underscores the central government's influence over states in India.