Wilbur attended public school and an academy at Phelps, N. Y. He studied law with his uncle, Sidney Edgerton.
After studies he taught school for a while, and in 1854 went to Akron, Ohio, where he continued teaching. In 1856 he was admitted to the bar and into partnership with his uncle.
With the outbreak of the Civil War in 1861 Sanders enlisted in the Federal army, and in October was commissioned first lieutenant, 64th Ohio Infantry. In 1862 he became acting assistant adjutant general on the staff of Gen. J. W. Forsyth but his health failed, and in August he resigned.
The next spring he accompanied Sidney Edgerton, who had been appointed territorial chief justice, to Bannack, in what was then eastern Idaho. In this mining camp, which was soon to become the first capital of Montana, he began the practice of law. The country was terrorized by "road agents" who held up stages and wagon trains and killed with reckless freedom, and when a particularly atrocious murder in December 1863 aroused some miners to arrest the murderers, Sanders was the only lawyer who dared undertake the prosecution. Despite threats by friends of the accused, he secured the conviction and speedy execution of the criminals.
He was Republican candidate for delegate to Congress in 1864, 1867, 1880, and 1886, and each time was defeated. He was a delegate to the Republican National Convention in 1868, 1872, 1876, and 1884, and from 1873 through 1879 he sat in the territorial legislature.
When Montana was admitted as a state in 1889, the legislature elected Sanders one of the first United States senators, and he drew the short term (Jan. 1, 1890 - Mar. 3, 1893). The election was contested, but Sanders and the other Republican candidate were seated by the Senate. His vagueness on the question of silver doubtless lost him support in Montana, and at the end of his term the Republican legislature did not reelect him. He diaed on 7 Jul 1905 in Helena, Montana, USA.
Being a Republican, he urged legislation allowing citizens the right to cut timber from the public domain and sought federal money for irrigation projects, to make the Missouri River navigable to Great Falls, and for various state purposes.
He spoke bitterly against the rising Populists and in the Republican state convention of 1896 savagely attacked the free-silver stand of the majority. In one of his last speeches he criticized the technical rulings of the supreme court in language so violent that newspapers did not dare print his address.
His power of sarcasm and ridicule aroused dread in his opponents.
On Oct. 27, 1858, he married Harriet P. Fenn; to this union five children were born.