US SUPREME COURT DECISIONS

The transportation of livestock from state to state is a branch of interstate commerce, and any specified rule or regulation in respect of such transportation, which Congress may lawfully prescribe or authorize and which may properly be deemed a regulation of such commerce, is paramount throughout the Union.

When the entire subject of the transportation of livestock from one state to another is taken under direct national supervision and a system devised by which diseased stock may be excluded from interstate commerce, all local or state regulations in respect of such matters and covering the same ground will cease to have any force, whether formally abrogated or not, and such rules and regulations as Congress may lawfully prescribe or authorize will alone control. The power which the states might thus exercise may in this way be suspended until national control is abandoned and the subject be thereby left under the power of the states.

The Act of Congress of May 29, 1884, 23 Stat. 31, c. 80, known as the Animal Industry Act, does not cover the whole subject of the transportation of livestock from one state to another.

The statute of Colorado of March 21, 1886, relating to the introduction of infectious or contagious diseases among the cattle and horses of that state, relates to matters not covered by the Animal Industry Act of Congress, and is not in violation of the Constitution of the United States.

No one is given by the Constitution of the United States the right to introduce into a state, against its will, livestock affected by a contagious, infectious or communicable disease, and whose presence in the state will or may be injurious to its domestic animals. The state -- Congress not having assumed charge of the matter as involved in interstate commerce -- may protect its people and their property against such dangers, taking care always that the means employed to that end do not go beyond the necessities of the case or unreasonably burden the exercise of privileges secured by the Constitution of the United States.

The Colorado statute is not inconsistent with the clause of the Constitution declaring that the citizens of each state shall be entitled to all privileges and immunities of citizens in the several states, for it is applicable alike to the citizens of all the states.

The principle is universal that legislation, whether by Congress or by a state, must be taken to be valid unless the contrary is made clearly to appear. chanrobles.com-red

Page 187 U. S. 138

The case is stated in the opinion.