According to his family, McIntosh made his way via the secret network of abolitionists and safe houses known as the Underground Railroad. Many freedom seekers who headed north continued onto Canada, but McIntosh stopped in Detroit, Michigan where there was an established African American community.
Between August 1863 and February 1864, a total of 895 men from across Michigan signed the rolls for the new regiment. The unit received its commission into the service of the United States as the First Michigan Colored Infantry on February 17, 1864. Its' designation changed to the 102nd U.S. Colored Troops/Infantry (USCI) on May 23. Henry McIntosh served as a private in Company G.
Pressure from the governors prompted the War Department to muster-out the Black troops and send them home, essentially removing their presence from Southern states. The 102nd mustered-out September 30, 1865. They arrived in Detroit, Michigan on October 17 and received their final pay and discharge.
Shortly thereafter, Henry McIntosh made his way to Lake County, Illinois, seeking new opportunities, and settling in Lake Forest. One attraction to the area was the number of African Americans living there. This is likely where he met Sarah Martin, whom he married in 1869. According to the 1870 Census, there were eight African American households, totaling 30 people, in Shields Township/Lake Forest.
View of 1870 U.S. Census data for Henry McIntosh, misspelled "Mackintosh" and his wife Sarah. Ancestry.com.
Over one year later, on July 14, 1885, Henry married Fannie Davis Freleigh (1867-1960).
Son, Clarence Nathaniel McIntosh (1889-1963) served as Sergeant Major with the 351st Field Artillery during World War I; son, Wayman Hillis McIntosh (1900-1982), an athletic trainer at Lake Forest College, volunteered as air raid warden during World War II; grandson, Henry Nathaniel McIntosh (1923-1980) served as lieutenant in the U.S. Navy during the Korean War; and grandson Clarence Pearson McIntosh (1925-1999) served as a lieutenant in the U.S. Navy.