Working late into the night, the U.S. Senate on July 7 overwhelmingly approved a bill establishing a national standard for labeling foods made with genetically engineered (GMO) ingredients, pre-empting a patchwork of state-by-state standards, including a Vermont law that went into effect six days earlier. The Senate passed the compromise measure, 63-30, at 10:45 p.m.

American Farm Bureau Fed­eration President Zippy Duvall and other agricultural leaders praised the Senate action and urged the House of Representatives to also pass the legislation before adjourning for the remainder of the summer on July...