The U.S. Constitution provides that Congress shall have the power to "borrow money on the credit of the United States". Congress has exercised that power by authorizing Federal Reserve Banks to issue Federal Reserve Notes. Those notes are "obligations of the United States" and "shall be redeemed in lawful money on demand at the Treasury Department of the United States, in the city of Washington, District of Columbia, or at any Federal Reserve bank". Federal Reserve Notes are designated by law as "legal tender" for the payment of debts. Congress has also authorized the issuance of more than 10 other types of banknotes, including the United States Note and the Federal Reserve Bank Note. The Federal Reserve Note is the only type that remains in circulation since the 1970s.
What power was Congress given by the Constitution?
borrow money on the credit of the United States

If Mammalia is considered as the crown group, its origin can be roughly dated as the first known appearance of animals more closely related to some extant mammals than to others. Ambondro is more closely related to monotremes than to therian mammals while Amphilestes and Amphitherium are more closely related to the therians; as fossils of all three genera are dated about 167 million years ago in the Middle Jurassic, this is a reasonable estimate for the appearance of the crown group. The earliest known synapsid satisfying Kemp's definitions is Tikitherium, dated 225 Ma, so the appearance of mammals in this broader sense can be given this Late Triassic date. In any case, the temporal range of the group extends to the present day.
Which group are Ambondro's closely related to?
monotremes

While slaveholding was slightly less concentrated than in some Southern states, according to the 1860 census, more than 330,000 people, or 33% of the population of 992,622, were enslaved African Americans. They lived and worked chiefly on plantations in the eastern Tidewater. In addition, 30,463 free people of color lived in the state. They were also concentrated in the eastern coastal plain, especially at port cities such as Wilmington and New Bern, where a variety of jobs were available. Free African Americans were allowed to vote until 1835, when the state revoked their suffrage in restrictions following the slave rebellion of 1831 led by Nat Turner. Southern slave codes criminalized willful killing of a slave in most cases.
In 1860, what percent of the North Carolina population were slaves?
33