In 1836, French helped form and was elected president of the New Bedford Young Men's Anti-Slavery Society. In 1838, he hired
Frederick Douglass to work as a caulker on one of his ships. Douglass, however, was unable to take the job because he was informed that every white man on the ship would leave if he "struck a blow upon her". 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." This amendment was opposed by
William Lloyd Garrison and defeated. 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. French was a member of the
Whig Party, but was not liked by the party establishment. 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. In addition to his work with the abolition movement, French was also active with the
temperance movement and at town meetings. His involvement with the temperance movement was criticized by Samuel Rodman, who believed that French's commitment to temperance was secondary to his commitment "to the ascendency of his political friends". In 1852, French was the Free Soil candidate for the
United States House of Representatives in
Massachusetts's 1st congressional district. French was a delegate to the Massachusetts Constitutional Convention of 1853. In 1878 and 1880, French ran for the U.S. House of Representatives as a member of the
Prohibition Party. He finished third in 1878 and fourth in 1880. '''1852 General Election for the United House of Representatives, Massachusetts's 1st congressional district''' •
Zeno Scudder (W) – 5,095 (49.7%) • John Pierce (D) – 1,905 (28.6%) • Rodney French (FS) – 1,801 (21.7%)
1852 New Bedford Mayoral Election • William J. Rotch – 875 (71.0%) • Rodney French – 357 (29.0%)
1853 New Bedford Mayoral Election • Rodney French – 1,052 (50.7%) • William J. Rotch – 1,022 (49.3%)
1854 New Bedford Mayoral Election • Rodney French – 1,581 (54.1%) • Willard Nye – 1,340 (45.0%)
1855 New Bedford Mayoral Election • George Howland Jr. – 1,836 (72.0%) • Rodney French – 715 (28.0%)
1856 New Bedford Mayoral Election • George Howland Jr. – 1,382 (50.5%) • Rodney French – 1,352 (49.5%)
1864 New Bedford Mayoral Election • George Howland Jr. – 1,349 (60.9%) • Rodney French – 867 (39.1%) '''1878 General Election for the United House of Representatives, Massachusetts's 1st congressional district''' •
William W. Crapo (R) – 12,575 (62.3%) • Matthias Ellis (D) – 7,383 (36.6%) • Rodney French (P) – 219 (1.1%) '''1880 General Election for the United House of Representatives, Massachusetts's 1st congressional district''' •
William W. Crapo (R) – 16,384 (69.9%) • Charles G. Davis (D) – 6,669 (28.4%) • Whitman Chace (
G) – 150 (0.6%) • Rodney French (P) – 126 (0.5%) • Henry B. Maglathhia (I) – 117 (0.5%) ==Commodore of the Stone Fleet==