we had stated the reason for labor organizations, — that through united action employees might have “opportunity to deal on an equality with their employer,” referring to what we had said in American Steel Foundries v. Tri-City Central Council, 257 U. S. 184, 209. And in recognition of this .light, we' concluded that Congress could safeguard it in the interest of interstate commerce and seek to make appropriate collective action “an instrument of peace rather than of strife.” To that end Congress enacted the National Labor Relations Act.
To attain its object Congress created a particular agency, the National Labor Relations Board, and established a special procedure. The aim, character and scope of that special procedure are determinative of the question now before us. Within the range' of its constitutional power, Congress was entitled to determine what remedy it would provide, the way that remedy should be sought, the extent to which it should be afforded, and the means by which it should be máde effective.
Congress declared that certain labor practices should be unfair, but it prescribed a particular method by which such practices should be ascertained and prevented. By the express terms of the Act, "the Board was made the exclusive agency for that purpose. Section 10 (a) provides:3
“The Board is empowered, as hereinafter provided, to prevent any person from engaging in any unfair labor practice (listed in section 8) affecting commerce. This power shall be exclusive, and shall not be affected by any other means of adjustment or prevention that has been or may. be established by agreement, code, law, or otherwise.”
The Act then sets forth a definite and restricted course of procedure. A charge of an unfair labor practice may.