He was known as having early in 1849 fought the battle of anti-slavery as a "Free Soil Whig," and later as a leading Republican member of Congress from Massachusetts.
Principally, however, he was suited to his post by education, family, and character.

He had been taken as a boy to Russia during his father's ministry at St.Petersburg, and later had been educated in England.

His father and grandfather, John Quincy Adams and John Adams, both Presidents of the United States, had both, also, been American Ministers at London.

Intensely patriotic, but having wide acquaintance through training and study with European affairs, especially those of Britain, and equipped with high intellectual gifts, Adams was still further fitted to his new post by his power of cool judgment and careful expression in critical times.

His very coolness, sometimes appearing as coldness and stiff dignity, rendered him an especially fit agent to deal with Russell, a man of very similar characteristics.