Lacey was born in
New Martinsville,
Virginia (now
West Virginia). He moved to
Iowa in 1855 with his parents, who settled in
Oskaloosa. He attended the common schools and pursued classical studies. He also engaged in agricultural pursuits, and learned the trades of bricklaying and plastering. In the spring of 1861, when Lacey was twenty years old, the
American Civil War began. Lacey joined an infantry in the
Union Army in May 1861. He initially enlisted in Company H,
3rd Iowa Volunteer Infantry Regiment. During his time with the Third Iowa Infantry, he was captured at the Battle of Blue Mills. However, he was soon released on parole. He afterward served as sergeant major in Company D,
33rd Iowa Volunteer Infantry Regiment. According to the November 1903 Congressional Directory, Lacey was promoted to lieutenant and reassigned to Company C of that regiment, then "promoted to assistant adjutant-general on the staff of
Brig. Gen. Samuel A. Rice, and after that officer was killed in battle was assigned to duty on the staff of
Maj. Gen. Frederick Steele". He remained in this position until the end of the war. As the war concluded, he studied law, was admitted to the bar in 1865, and began to practice law in Oskaloosa. Five years later, he became a member of the
Iowa House of Representatives. He was elected to the
Iowa House of Representatives for a term beginning in 1870. He was later elected to the Oskaloosa City Council in 1880, serving until 1883. He served one term as city solicitor. In 1878, he founded the town of
Lacey, Iowa, to route the
Iowa Central Air Line Railroad. On April 12, 1902, Lacey accepted membership into the
Boone and Crockett Club, a wildlife conservation organization founded by
Theodore Roosevelt in 1887. ==Congressional service==