This discovery coincided with the suppression of abolition propaganda in the South.
Hitherto John Quincy Adams had favored the western expansion of our territory.

He had labored diligently to make the Rio Grande the western boundary of the Louisiana Purchase at the time of the treaty with Spain in 1819.

But though in 1825 he had supported a measure to purchase Texas from Mexico, under the new conditions he threw himself heartily against the annexation of Texas, and in 1838 he defeated in the House of Representatives a resolution favoring annexation.

To this end Adams occupied the morning hour of the House each day from the 16th of June to the 7th of July, within two days of the time fixed for adjournment.
This was only a beginning of his fight against the extension of slavery.
There was no relenting in his opposition to pro-slavery demands until he was stricken down with paralysis in the streets of Boston, in November, 1846.

He never again addressed a public assembly.