In a historical point of view on federalism, which corresponds to a broad context, it's like the balance between forces, its purpose is "simultaneously to generate and maintain both unity and diversity" according to Daniel J. Elazar, then conserving the autonomy of each state.
In a local context, we can observe that in 1787, during the crisis that was raging at the time, a convention was held in which delegates from the 13 states were invited to the capital of the country: Philadelphia, Pennsylvania. To discuss and review articles of the Confederation that had the proposal of a strong and central State.
In other context, federalists and anti-federalists represent the birth of the United States, each side with its oppositions, giving the opposition the opportunity to make collections, nor allowing larger states to swallow smaller states and the emergence of a centralized state.
