Holding that section 10(b) limitations period begins to run when the employee "discovers, or in the exercise of reasonable diligence should have discovered, the acts constituting the alleged [violation]"
In NLRB v. Stowe Spinning Co., 336 U.S. 226, 232-33, 69 S.Ct. 541, 544, 93 L.Ed. 638 (1949), the Court declined to enforce an order requiring an employer to make its meeting hall available to a union; the Board might legitimately bar discrimination against unions, the Court said, but could not require the employer to prefer unions over other potential users.