The elastic clause of the United States Constitution, which was a factor in the McCullough v. Maryland (1819), gives Congress the power to

Establish a national bank

Explanation:

The elastic clause enable the government to do something that does not specifically mentioned within the constitution as long as they do not directly violate the existing rule. This clause was made because the scope of duties for government tend to be really large and this clause can add more flexibility to the government's program.

The constitution did not granted the government with the power to established a federally owned bank.

But, the constitution does not directly banned the government from doing so. Because of the elastic clause, this means that establishing a national bank would be considered as legal under the constitution.