Noah L. Jeffries was born on December 3, 1828, in Pennsylvania. He eventually moved to Ohio, and he married Minerva E. Tidball on January 16, 1851. Their daughter Henrietta was born around 1852. He worked as a lawyer in Mansfield, Ohio, and by 1860, he owned $1,200 of real estate and $600 of personal property.
In the fall of 1861, he received a commission as a 1st lieutenant in the 59th New York Infantry. In April 1862, he was promoted to captain and assistant adjutant general. He later became colonel of the 20th Veteran Reserve Corps. He mustered out on August 26, 1866.
He served as inspector general of the Maryland National Guard in the late 1860s. According to an early biographer, he “completely reorganized the military branch of the State Government.” He resigned in March 1869 and moved to Washington, D.C. He worked as a lawyer, and by 1870, he owned $12,000 of real estate and $5,000 of personal property. He divided his time between Washington and Philadelphia, Pennsylvania. He died of heart disease in Washington on April 22, 1896.