In the summer of 1787, as the Constitutional Convention convened, another convention was taking place in the city of Philadelphia: a gathering of the Pennsylvania Society for Promoting the Abolition of Slavery, which believed that slavery -- not the public debt -- was the nation's greatest peril.

Knowing that the other convention was writing a constitution, the abolitionist society drew up a petition calling for a provision banning "the African trade in the United States."

"In vain will be" Americans' "Pretentions to a love of liberty or regard for national Character while they share in the profits of a Commerce that can only be conducted upon Rivers of human tears and Blood," the petition said.

Tenche Coxe, the secretary of the society, was supposed to present the petition to Benjamin Franklin, who would be asked to bring it to the attention of the convention. Coxe gave it to Franklin all right, but he did it in such a way as to make sure it would never see the light of day at the convention.

Coxe later described what he did: "A very strong paper was drawn and put into my hands to procure the signature of Dr. Franklin to be presented to the federal convention. I enclosed {it} to the Dr. with my opinion that it would be a very improper season and place to hazard the Application considering it was an over zealous act of honest men."

Franklin must have agreed, for he said not a word about the petition or about the slave trade. In fact, hard-boiled as Coxe's view was, he was correct to assume there was virtually no chance the convention would try to abolish the trade. Of the 55 convention delegates, about 25 owned slaves. Some, like George Mason of Virginia, owned hundreds.

While several northern delegates (Franklin and Gouverneur Morris among them) belonged to abolitionist groups, and others had pushed their states toward abolition, no one who understood politics in 1787 believed that either emancipation or suppression of the slave trade was politically possible.

The presence of abolitionists in Philadelphia was one of the things, along with the horseflies, that made southern slaveholders uncomfortable about coming there with servants. Slaveholders complained that abolitionists enticed slaves away or absconded with them, and slaves sometimes got the urge to run once in the City of Independence.

The papers offered rewards for their return, along with notices for lost watches, clothing and indentured servants. "Forty dollars reward," said one ad that appeared while the convention was meeting. "Ran away from the subscriber . . . a Negro fellow . . . much addicted to lying and can invent the most plausible account of himself."

"Twenty Dollars Reward," said another ad. "Ran away from the subscriber . . . a Mulatto wench, named Chloe . . . She is a stout, well-featured wench, nearly 22 . . . a plausible, cunning hussy."