Silas Grimes was born on November 7, 1839, in Indiana to Thomas and Nancy Grimes. His father was a farmer who owned $1,200 of real estate by 1850. Grimes grew up and attended school in Perry, Indiana, and his father died in 1854. By 1860, the family was living in Clear Creek, Indiana, and Grimes was working as a farm laborer.
On September 5, 1861, Grimes received a commission as a 1st lieutenant in Company G of the 31st Indiana Infantry. The regiment took part in the Battle of Fort Donelson, the Battle of Shiloh, the Siege of Corinth, the Battle of Perryville, the Battle of Stones River, the Battle of Chickamauga, the siege of Chattanooga, the Atlanta campaign, and the Battle of Nashville. He was promoted to captain in October 1862, then to major on November 22, 1864. He may have received a brevet promotion to lieutenant colonel on March 13, 1865. He mustered out on December 8, 1865.
In early 1863, he confessed to his sister that he wanted to return home. He assured her, however, that he “didt intend to convey the Idea that I was coming dishinorble or that I was tired of the Service on the account of the [Emancipation] Proclamation.” He denounced northern Peace Democrats, explaining that “I don’t want to fight Rebels abroad for two years and then go home and find Rebel sympathizers righ[t] among my own relatives.” He urged his sister not to “let the Negro corrupt your patriotism.” If “evry slave in the united States should be freed and the Government saved I would think it all right myself.” He viewed emancipation as a military necessary: “It becomes necessary now that the Slaves should be taken from disloyal slaveholders Slavery has been the main staks for the Confederacy while they have turned out evry effective white to fight us they have had the Negro to rais them subsistence."
Grimes returned to Clear Creek after the war. He married Susan Gaither on March 12, 1868, and they had at least nine children: Martha, born around 1869; Luther, born around 1870; Perry, born around 1872; John, born around 1873; Mary, born around 1875; Nancy, born around 1877; Irvin, born around 1879; Silas, born around 1882; and Annie, born around 1888. Grimes worked as a farmer, and by 1870, he owned $6,000 of real estate. He helped care for his elderly mother and his sisters, Mary and Louisa.
Grimes applied for a federal pension in February 1884 and eventually secured one. Grimes supported the Republican Party, and in 1886, he was the party’s candidate for county auditor. He initially seemed to lose the election by 43 votes, prompting him to call for a recount. As a local writer explained, “it is now charged that there are gross irregularities in the returns from several precincts…Democrats pretend to be very indignant at the procedure, which is all the more assurance to Republicans that there is something radically wrong.” The recount revealed that Grimes secured a slim majority of 4 votes. His Democratic opponent appealed the case to the commissioners’ court and then to the circuit court, but both courts upheld Grimes’ victory.
He retired in the 1910s, and by 1920, he and Susan were living in Bloomington, Indiana. He died there on August 24, 1927.