How did the free Blacks in Philadelphia encourage Ona to seek her own freedom?

Ona was most likely influenced by the emancipation movement when she escaped from the President´s official residency.

Explanation:

Ona Judge (1773 - 1848) spent six years in Philadelphia, as a slave at President Washington’s House. There, Ona discovered a strong abolition movement led by organizations such as the Pennsylvania Abolition Society, which was increasingly succeeding in the emancipation of the black population.

The Washingtons were pressured by such organizations to follow the Act for the Gradual Abolition of Slavery, which required all slaves transported to Pennsylvania should be emancipated after six months.

the  wilmot proviso  was designed to eliminate  slavery  within the  landacquired as a result of the mexican war (1846-48). fearing the addition of a pro-slave territory, pennsylvania congressman david  wilmot proposedhis amendment to the bill.