Final answer:
Federalism in the United States has been dynamic since the 1960s, with events such as the era of cooperative federalism, the rise of new federalism, and state-level policy innovations.
Step-by-step explanation:
Since the 1960s, federalism in the United States has been dynamic rather than static. One event that exemplifies this is the era of cooperative federalism, where the federal government took an active role in addressing national problems and expanded the size of the federal administrative apparatus. Another event is the rise of new federalism during the Nixon and Reagan administrations, which aimed to decentralize policies and give more authority to the states. Finally, federalism has evolved through policy innovations at the state level, such as California's environmental policies and the health insurance exchanges run by select states.