SpaghettiOs were invented in 1965 by Ralph Miller, PhD. working for the Campbell Soup Company. He had already made a very important contribution to Campbell's Franco-American division with the discovery that pasta did not need to be cooked before being placed in the can. SpaghettiOs were not nearly as revolutionary an idea as that, but were developed in response to market research that indicated that an easy to serve spaghetti product marketed for kids would probably do well.
In their original form, SpaghettiOs were pasta rings in four sizes (ditali, ditalini, tubetti, and tubettini) in a tomato and cheese sauce. The line has expanded since then, and now includes SpaghettiOs with meatballs, SpaghettiOs with franks, and SpaghettiOs plus calcium. There are also assorted spin-offs
such as RavioliOs, TeddyOs, and Where's WaldOs. Apparently 90 million pounds of this stuff gets eaten every year.
Campbells likes to make nutritional claims about SpaghettiOs. The current claim is that a serving of SpaghettiOs provides "A full serving of veggies & grains".
I find this amusing considering that one serving also contains more than a gram of sodium and 3.5g of saturated fat. Not that that would ever keep me from eating the tasty little things. One of the least healthy (and one of my favorite) ways to eat SpaghettiOs is cold, right out of the can, using a piece of beef jerky as a spoon, while fishing.
Sources:
www.spaghettios.com
http://www.goodbyemag.com/apr01/miller.html
SpaghettiOs with meatballs can label