During his terms in Congress, he proposed to end the slave trade in the District of Columbia and gradually abolish slavery across the city.

He attended the public schools of Norwich and moved with his brother Asher Miner in 1797 to his father's lands in the Wyoming Valley, and to Wilkes-Barre, Pennsylvania, in 1802.

During his term, he promoted internal improvements to roads and canals, aid for the poor, compulsory vaccines for kinepox, and the regulation of bank currency.

[9] However, he had to leave his newspaper business when he was elected to the United States House of Representatives for Chester, Delaware, and Lancaster counties in 1824.

[12] He introduced his plan to immediately end the slave trade in the District of Columbia and gradually abolish slavery in the capitol over a period of about ten years.

Miner thought that immediate, nationwide abolition was impossible, but he hoped that if the District of Columbia could successfully abolish slavery, it would act as a “lever” to influence the rest of the country to do likewise.

He tried to readdress the plan in December 1826, but he was encouraged not to speak because the topic provoked excitement and irritation, especially among the Southern representatives.

For this is not like the former, carried on against a barbarous nation; its victims are reared up among the People of this Country; educated in the precepts of the same religion; and imbued with similar domestic attachments.

All black people in the District of Columbia were assumed to be slaves unless they could provide proof for their freedom, so free men were often mistaken for runaways, arrested, and sold into slavery.

[16] In Miner's final speech, he recalled the cruelty he witnessed, exposing the House to the brutal reality of the slave trade.

Most notably, he published a series of ethical stories titled From the Desk of Poor Robert the Scribe, which he composed while editing the Luzerne Federalist.

gained national popularity, in which Miner allegedly coined the phrase "to have an ax to grind," although the saying is commonly attributed to Benjamin Franklin.

After completing his second term in Congress, Miner decided not to run again because he was growing deaf and could not fully participate in the sessions.