How did McCulloch v. Maryland establish the implied powers doctrine? 1. It allowed Congress to establish a post office even though it was not expressed in the Constitution; 2. It allowed Congress to declare war even though it was not expressed in the Constitution; 3. It allowed Congress to collect taxes even though it was not expressed in the Constitution; or 4. It allowed Congress to create a national bank even though it was not expressed in the Constitution

4. It allowed Congress to create a national bank even though it was not expressed in the Constitution.

McCulloch v. Maryland was a landmark Supreme Court case decided in 1819. The case involved a dispute between the state of Maryland and the federal government over the constitutionality of the Second Bank of the United States. The state of Maryland attempted to impose a tax on the bank, which the bank's cashier, James McCulloch, refused to pay.

The Supreme Court, in a unanimous decision written by Chief Justice John Marshall, held that Congress had the power to create a national bank under the Necessary and Proper Clause of the Constitution. This clause, found in Article I, Section 8, grants Congress the power to make all laws necessary and proper for carrying out its enumerated powers.

In establishing the implied powers doctrine, the Court reasoned that the creation of a national bank was an implied power necessary for Congress to carry out its enumerated powers, such as the power to regulate commerce and collect taxes. The Court concluded that the necessary and proper clause should be broadly interpreted to enable the federal government to effectively carry out its functions.

Therefore, by affirming the constitutionality of the national bank, McCulloch v. Maryland established the implied powers doctrine, asserting that Congress had the authority to take actions not explicitly listed in the Constitution if those actions were necessary and proper for achieving its enumerated powers.