Genetically engineered (GE) crop varieties have been prominent in US agriculture for many years. First commercialized in the 1990s, they were rapidly adopted by farmers. By 2014, 93 percent of corn and 94 percent of soybean acres were planted with these varieties. Favorable reception of these products was never universal, as objections were voiced by some segments of the public; however, it seems fair to say that the acceptance of this new technology was smoother in the United States than elsewhere. This conclusion has been tested over the last few years by an increased public awareness and activism intended to bring about new legislative action on genetically modified organisms (GMOs), as GE products are often called. Such efforts have specifically aimed to introduce state-level requirements for mandatory food labeling of GMO content. Proposition 37, put to California voters in 2012, squarely aimed at mandating such labeling. Although defeated at the polls, it brought much publicity to this issue. Similar initiatives were also narrowly defeated in the states of Washington (2013) and Colorado and Oregon (2014). However, Vermont enacted mandatory GMO labeling legislation in 2014, and Maine and Connecticut have approved bills that would trigger such labeling under certain conditions (related to neighboring states also mandating GMO labeling), and several other states are considering similar actions. Are we witnessing the dawn of mandatory GMO labeling in the United States, and would that be a desirable outcome?