Authority a government is assumed to have in order to perform its constitutionally prescribed duties. These powers are not specifically enumerated; rather, they constitute the unwritten methods a government may employ in order to exercise its enumerated powers.
In its earliest and most renowned implied powers case, McCulloch v. Maryland
After McCulloch, the implied powers were used to expand (Gibbons v. Ogden, 1824) and contract (United States v. Lopez, 1995) governmental power. Although many of the cases decided by the Court dealt with economic policies, the Court also addressed crime prevention programs, federalism cases, and the implied powers of the presidency. Indeed, the majority of presidential powers are based on authority implicit in such enumerated, yet vague, powers as the commander in chief and executive power clauses of the Constitution.
McCulloch v. Maryland