2. In the United States the census is the only means by which Congress determines the number of Representatives each State is entitled to have in that body. Hence the Constitution itself makes provision for the enumeration of the people once in ten years—called a decade. The first was made in 1790, the next in 1800, and so on every tenth year. If the number of any year ends with a cipher, we know that the United States census was taken, or will be taken, in that year, whether we look backward or forward. 3. Up to the present time, according to the provisions made in the Constitution, a census has been taken nine times, and under the head of recapitulation (see index) we find what it was each time. We also find that from the first (1790), to the last (1870), the population had increased from 3,929,827, to 38,838,180. Therefore it approximates very nearly to 40,000,000; indicating a growth unparalleled by any nation in ancient or modern times. We will next state how this great national work is performed. The Constitution simply declares that it shall be done, but the laws specify _how_ it shall be done, and _who_ shall do it. The United States Marshals are the officers designated by the law as the persons who shall make the enumeration of the people in each State and Territory; in addition to which they are also required to procure other statistical matter, as directed by Congress. 4. In order to accomplish this work, it is necessary to employ a number of assistant marshals, one of whom must visit every house in his district, and ascertain the number of persons belonging to it, together with such statistical information as is required. This is all returned to the Marshal, and by him sent to the Department of the Interior at Washington, where, under the direction of the Secretary of the Interior, it is made into a report, and then laid before Congress, to be used by it in apportioning to the States their quota of Representatives. This apportionment is actually made in the Department of the Interior, and then laid before Congress for its examination and approval. The Marshal appoints and commissions his deputies, who must be sworn to perform the duties assigned to them, to the best of their ability.