Our burdens are heavy & call loud for justice! call loud for mercy! I Therefore, take the liberty Sir, to address you myself upon the subject of slaviry, and ask you a few questions respecting Mr. Duane’s politicks
Observation: The heaviness that the slaves felt from being in slavery and wanting justice and being shown mercy and wanted to ask Thomas Jefferson Questions.
Interpretation:This sentence in the letter was describing the emotion that the anonymous slave felt and also others that was slaves which was feeling burden and wanting to seek justice while also want to experience mercy.
The anonymous had a deep emotions on how the slave had to endure during their time of being oppressed and while wanting to bring justice and also wanting to bring mercy to the slaves.
This is context.