Which came first, the chicken or the egg? Silly question. But if you're talking about chicken as we know it today — barbecued, boneless and skinless, served as sausages, bologna, nuggets, and burgers — the answer is actually "neither". What came first was Robert C. Baker, a Cornell University food scientist who is credited with popularizing chicken as a convenient, everyday meat.
At Slate, Maryn McKenna has a really interesting piece about Baker's role in the invention of the chicken nugget. Although you've probably heard that the nugget was invented by McDonald's research and development staff, Baker actually beat them to the punch by a couple decades, turning out "chicken sticks" in 1963. The catch is that, as a researcher at a publicly funded university whose primary goal was to increase the profitability of family-operated chicken farms in upstate New York, Baker never patented his own ideas.
Baker's prototype nugget, developed with student Joseph Marshall, mastered two food-engineering challenges: keeping ground meat together without putting a skin around it, and keeping batter attached to the meat despite the shrinkage caused by freezing and the explosive heat of frying. They solved the first problem by grinding raw chicken with salt and vinegar to draw out moisture, and then adding a binder of powdered milk and pulverized grains. They solved the second by shaping the sticks, freezing them, coating them in an eggy batter and cornflake crumbs, and then freezing them a second time to -10 degrees. With trial and error, the sticks stayed intact. Baker, Marshall, and three other colleagues came up with an attractive box, designed a dummy label, and made enough of the sticks to sell them for 26 weeks in five local supermarkets. In the first 6 weeks, they sold 200 boxes per week.
You can read the rest of McKenna's piece at Slate. But I also wanted to add a couple of other interesting links to this.
First, I found an extract from an article Baker published in the Cornell Hospitality Quarterly in May of 1962. The article doesn't mention chicken nuggets. Instead, it's about the research that led up to the invention of the nugget, as Baker figured out how to produce chicken hotdogs and smoked chickens that could be frozen and sold pre-cooked. It's an interesting look inside the process that McKenna writes about — Baker's efforts to shift chicken from a messy and/or time-consuming task, to something that could be quickly and easily prepared by even working mothers.
Second, McKenna mentions in the article that Baker is also the source of a famous barbecued chicken recipe that has become a staple of the New York State Fair. At the Cornell Library website, I found a pamphlet about Cornell Chicken written by Baker. It includes his original recipe (with serving portions ranging from five people to 300), his directions for building a barbecue fire pit, and a helpful selection of suggested side dishes.