J. Robert Osborne
Slavery was an elusive institution to define legally for early Americans. It evolved socially and economically as a local phenomenon and it became entrenched in certain areas of colonial America before there ever was a thought about the possibility of a national and independent government. The laws that governed it were local and the greatest authority responsible for those laws would have been the colonial legislatures and royal governors.
The institution of the plantation with slave labor was imported from the sugar islands of the Caribbean and supplied by the Atlantic Slave Trade. The men and women of African ancestry that worked as slaves on the plantation were thought of as someone else's property with limited rights and maximum accountability. The first consideration legally was to the rights of the slave owner and not the slave. The economic investment in a human being as a source of labor prioritized the retention of the slave and the return of the enslaved person if they sought to runaway to freedom. The other legal requirement for maintaining the plantation system was to construct a legal framework that had maintaining the public safety in case of slave rebellion as its first priority. Any rights of the slave were subsumed in meeting the two goals and in fact slaves were prevented from learning to read and to legally marry in order not to reduce their value as to a potential sale at anytime.
As slavery waxed and waned in different areas and immigrants of African ancestry came to America the freemen or non-slave Black population grew. Because dark skin color was associated with slavery the colonists of European descent were often suspicious of the free status of men and women who could have been enslaved and escaped. Papers were often required to prove manumission and status and the civil rights of freemen were precarious as opposed to those people of European descent. In the northern colonies the number of freemen, though relatively small, far exceeded the number of slaves after a time and in the southern colonies the number of slaves was much larger and far exceeded the small number of freemen.
Slavery was legal in all thirteen English colonies before the colonies declared their independence from Great Britain. Eventually, seven of the original colonies outlawed slavery but six retained it as an institution right up to the Civil War. When Thomas Jefferson, a slave owner, wrote the Declaration of Independence there was no reference to slavery although the document itself was to declare the independence of American colonists from Great Britain. Jefferson had written a short paragraph holding the King responsible for the institution of slavery in America but it was excluded at the behest of Southern slaveholders. The rights of man were not extended to the slaves in America. During the Revolutionary War, the British offered freedom, sanctuary and a rifle to any slave that would leave the plantation and fight for the British army. The British government saw the irony in the American slave owners claiming to be politically oppressed while economically, socially and legally oppressing the slaves they "owned".
The Second Continental Congress governed America throughout the Revolution and created the first national government according to The Articles of Confederation. During the time of the Articles prior to the adoption of the Constitution the Land Ordinance of 1785 and the Northwest Ordinance of 1787 established the process for land owned by the national government to be divided and sold and they established requirements for statehood. Congress declared that there was not to be slavery in the prospective states of the Northwest Territory, (then territory that became Ohio, Indiana, Illinois, Michigan and Wisconsin).