According to Zuri Allen of the California Right to Know Initiative, 971,126 signatures were collected.
Supporters arrived with ballot boxes and baby strollers, cheering the state's first ever ballot proposition to require the labeling of genetically modified organisms, known as GMOs.
"A genetically engineered food is a plant or meat product that has had its DNA artificially altered by genes from other plants, animals, viruses or bacteria in order to produce foreign compounds in that food," Allen said.
GMOs are created for plants to resist bugs or drought, or to develop flavor, for example. Yet many don't like Mother Nature being tampered with or being misled.
"I resent not knowing what I am buying," said Donna Miller, who holds a Ph.D. in nutrition.
Opponents, mostly small business owners, say they feel it's not really about the right to know, but rather the right to sue.
"They're targeting small family farmers and small neighborhood markets because they know they don't have the resources to defend themselves against frivolous lawsuits," said Maryann Marino, regional director of California Citizens Against Lawsuit Abuse.
Marino said it puts California farmers and food manufacturers at a disadvantage because they will have to label any product grown, produced or sold in the state. They point to other options, like organic foods, which have strict requirements and labeling, and do not allow any engineered ingredients.
The initiative wants labels for products sold in grocery stores and markets, but those very same products would be exempt in restaurants. There's also exemptions for meat, dairy, poultry and alcohol.
"My understanding is that they excluded it because we're trying to focus on what the major things that are being genetically modified," Allen said.
That's mainly soy, corn, cotton or cotton seed, which are abundant in about 70 percent of processed foods.