Twombly also participated in a number of other engagements in the Civil War, including the Siege of Corinth and Sherman's March to the Sea.

[1] Twombly enlisted in the Union Army on April 24, 1861, after President Abraham Lincoln had called for soldiers to counter the secessionist Confederate States.

[1] In February 1862, the Second Iowa Infantry Regiment was incorporated into the Army of the Tennessee, which was under the command of Major General Ulysses S.

[8]Twombly carried his regiment's colors during the April 1862 Battle of Shiloh and participated in the Siege of Corinth, Mississippi as an acting second lieutenant.

In 1863, Twombly's regiment was formally stationed in Corinth, and engaged in numerous actions against the cavalry forces of Confederate General Nathan Bedford Forrest.

[2] In October 1863, Major General William Tecumseh Sherman replaced Grant as the commander of the Army of the Tennessee.

While stationed in Savannah, Georgia in January 1865, Twombly was made the assistant inspector general of the Third Brigade of his division.

[2] From August to December 1865, Twombly attended Bryant & Stratton's Business College, a commercial school in Burlington, Iowa.

[1][7] Twombly, who had consistently supported the Republican Party since reaching voting age, accepted the position of treasurer of Van Buren County in 1880.

[1][12][13] After his term as Treasurer of Iowa had concluded, Twombly assisted with the creation of the Home Savings Bank of Des Moines.

[15] Their oldest son, William Tuttle Twombly, was born in 1870 and died shortly before his seventeenth birthday on December 28, 1887.