[5] At an 1841 meeting of the New England Anti-Slavery Society, French, along with fellow radical abolitionists Nathaniel Peabody Rogers and Stephen Symonds Foster, asked the convention to declare "that the church and clergy of the United States, as a whole, constitute a great brotherhood of thieves, inasmuch, as they countenance and support the highest kind of theft - manstealing" and to "renounce them as Christian Church and clergy."
[6] In September 1843, President John Tyler appointed French Collector of Customs for the Port of New Bedford.
However, once Tyler found out that he was a vocal opponent of slavery, he gave up on French's nomination and the Senate refused to confirm him.
[3] French also forwarded a petition demanding the repeal of the Fugitive Slave Act to U.S. Representative Horace Mann.
[8] In 1852, merchants in New Bern, North Carolina boycotted a ship partially owned by French because they considered him to be a leading opponent of the Fugitive Slave Act.
[3] In March 1851, French learned that a United States Marshal planned to raid the town for fugitive slaves.
After he observed an unfamiliar ship approaching the harbor, French rang a bell in Liberty Hall to warn local African-Americans.
Charles W. Morgan described French "verbose & violent" and possessing "the faculty and talent to outrun and distract every meeting he attends & he generally is successful".
[11] In 1852, French was the Free Soil candidate for the United States House of Representatives in Massachusetts's 1st congressional district.
[8][15] Upon his return, French showed off a number of "relics" he had retrieved from the South, including shells, shots, and pieces of a palmetto tree.