Pennsylvania: A Gradual Abolition Act of 1780
https://avalon.law.yale.edu/18th_century/pennst01.asp
This law, the Gradual Abolition Act of 1780, was the first extensive abolition legislation in the western hemisphere. It passed the Pennsylvania General Assembly on March 1, 1780. To appease slave owners, the act slowly emancipated enslaved people without making slavery immediately illegal. The act permitted Pennsylvania slaveholders to keep the enslaved individuals they already owned unless they failed to register them annually. At the same time, the act provided for the eventual freedom of individuals who were newly born into slavery.
Learn More About the Act at: https://www.mountvernon.org/library/digitalhistory/digital-encyclopedia/article/gradual-abolition-act-of-1780/
Washington, George. Letter to Oliver Wolcott, Jr. 1. Sept. 1796. Connecticut Historical Society, Oliver Wolcott. Jr Papers.
https://founders.archives.gov/documents/Washington/99-01-02-00910
Secretary of the Treasury, George Washington asks for help in retrieving his runaway slave - Ona Judge. This letter provides an example of George Washington discussing Ona Judge
Washington, George. “Letter to John Moss from George Washington", 30 May 1788,” Founders Online, National Archives. https://founders.archives.gov/documents/Washington/04-06-02-0270.
This letter provides the reader with evidence of how George Washington listed his slaves as property. It goes into great detail to show how he denoted their age and status.