The US Constitution, as of 1787:
Representatives and direct Taxes shall be apportioned among the several States which may be included within this Union, according to their respective Numbers, which shall be determined by adding to the whole Number of free Persons, including those bound to Service for a Term of Years, and excluding Indians not taxed, three fifths of all other Persons.
No person held to service or labour in one state, under the laws thereof, escaping into another, shall, in consequence of any law or regulation therein, be discharged from such service or labour, but shall be delivered up on claim of the party to whom such service or labour may be due.
Mistakes: entrenched a gross violation of human rights, contributed to Civil War. Cancelled for slaves by the Thirteenth Amendment, 1865. The Fugitive Slave Clause may theoretically still be in force for convicts condemned to forced labour, but has no practical application.
18th Amendment, 1919:
Section 1. After one year from the ratification of this article the manufacture, sale, or transportation of intoxicating liquors within, the importation thereof into, or the exportation thereof from the United States and all the territory subject to the jurisdiction thereof for beverage purposes is hereby prohibited.
Section 2. The Congress and the several States shall have concurrent power to enforce this article by appropriate legislation.
Mistake: unenforceable, unintended consequences. Repealed in its entirety 1933.
Second Amendment, 1791:
A well regulated militia being necessary to the security of a free state, the right of the people to keep and bear arms shall not be infringed.
Mistake: false premise, category error in identifying a contingent as a fundamental right, unintended consequences, obsolescence (end of threats from slave revolts and Indians, establishment of a large peacetime standing army and other military forces, [update] and uniformed police).
Still in force.