equity, . . . where the matter in controversy exceeds, exclusive of interest and costs, the sum'-or value of three thousand dollars, and (a) arises under the Constitution or laws of the United States, or- treaties made, or which shall be made, under their authority, or (b) is between citizens of different States, . . .” ■ .
This provision covers two distinct classes of suits. In one the distinctive feature consists in the fact that the suit arises under the Constitution, or a law or treaty, of the United States, the citizenship of the parties not. being an element; while in the other the distinctive feature consists in the fact that the parties are citizens of different States, the particular basis or ground of the shit not being an element. This suit was within the first class, and,%the requisite amount being involved, it came within the general jurisdiction of the District Courts as defined by § 24. ' ' ..
Section 51 deals with the venue of suits begun in those courts and provides, subject to exceptions not material here, that—
“. . . no civil suit shall be brought in any district court against any person by any original process or proceeding in any other district than that whereof he is an inhabitant; but where the jurisdiction is founded only on the fact that the action is between citizens of. different States, suit shall be brought only in the district of the residence of either the plaintiff or the defendant.”
This restriction, as repeatedly has been held, does not affect the general jurisdiction of a District Court over a particular cause, but merely establishes a personal privilege of the defendant, which he may insist on, or may waive, at his election, and does waive, where suit is brought in a district other than the one specified, if he enters an appearance without claiming his privilege. Central Trust Co. v. McGeorge, 151 U. S. 129; Interior Construction Co. v. Gibney, 160 U. S. 217; In re Moore,