In 1845, he successfully defended Marvin Pond ("People v. Pond") for harboring the fugitive slave John Hauley. In 1847, he lost a case ("Matson v. Rutherford") representing a slave owner (Robert Matson) claiming return of fugitive slaves. While a congressman from Illinois in 1846 to 1848, Lincoln supported the Wilmot Proviso, which, if it had been adopted, would have banned slavery in any U.S. territory won from Mexico. Lincoln, in collaboration with abolitionist Congressman Joshua R. Giddings, wrote a bill to abolish slavery in the District of Columbia with compensation for the owners, enforcement to capture fugitive slaves, and a popular vote on the matter. (Slavery in the District of Columbia was not ended until 1862, when Lincoln was president and there were no Southern senators.)