Thomas Fleming has an op-ed in the Wall Street Journal (hat tip Ann Althouse), discussing the colonies at the time of independence. The closest he comes to mentioning slavery is this: " In some parts of the South, 10% owned 75% of the wealth."
It's amazing how easy it is to exclude people. For example, Mr. Fleming above excluded the slaves. But I myself did not remember to include Native Americans. Were they "Americans" included in the Declaration? Are they "Americans" today? Certainly their status is more complicated than most other citizens of the country. When Jackson sent the Cherokees and Creeks on the Trail of Tears from Georgia to Oklahoma was he in effect taking away their citizenship in the U.S.?