Thomas Clarkson (28 March 1760 – 26 September 1846), was an English abolitionist, and a leading campaigner against the slave trade in the British Empire. He helped found The Society for Effecting the Abolition of the Slave Trade and helped achieve passage of the Slave Trade Act of 1807, which ended British trade in slaves. In his later years Clarkson campaigned for the abolition of slavery worldwide. In 1840, he was the key speaker at the Anti-Slavery Society (today known as Anti-Slavery International) conference in London, which campaigned to end slavery in other countries.