The Emerson family papers consist of 98 letters and 4 printed materials. The bulk of the letters are from Horace; his earliest letters are from Bridgton, Maine, in 1851-1852, and from Fond du Lac, Wisconsin, in 1856. He wrote to his mother, Sister Maria, and brother Irving (Irvey) about his life in the West, his health, hunting bear and deer, killing cats that kept him up all night, and of leaning the engineering trade. He also requested that his wedding announcement be placed in most of the Boston papers.
Horace often used expressive language when describing his surroundings and his acquaintances. In a letter from April 15, 1858, he described Milwaukee as "the worst place I was ever in[...]Gambling is called an honorable business." Of a female friend back east he remarked, "she would comb my hair with a 3 leg stool if she could get a chance." He wrote to Irving about the railroad running between Milwaukee and Portage City: "Monday we killed 2 hogs and one cow...I wish you could have seen the cow. When we hit her it took her right up 10 feet and set her on her ass in a mud hole" (May 5, 1858). In 1861, Horace wrote a few letters from Bridgton, Maine, where his father, re-married with two children, was making shingles for a living. By April, he was beck in Wisconsin, and enlisted in the Portage City Light Guard (Second Regiment Wisconsin State Volunteers, Co. C. He described the daily routine training at Camp Randall in Madison, Wisconsin, and noted to his musical brother that they had 3 fiddles, one flute, a guitar, bones, boxing gloves and dum bells "for the mussle." When his regiment got to Washington, he called on "old Abe" at the White House and had a brief meeting and drink with him. His letter of July 26, 1861, recounts his part in the Battle of Bull Run, fighting with other "tough cusses of Wisconsin." Horace spoke often of bravery and described the enjoyable aspects of being a solder, and, like many Union soldiers in the first years of the war, thought highly of "the good General McClellan" (March 12, 1862). By January 31, 1863, however, Horace was disillusioned with the war. He wanted to leave the army and was hostile to the idea of fighting to free blacks from slavery. By July 1863, Horace was back in Wisconsin and considered enlisting in the Minnesota militia to fight the Indians: "I will go to fight Indians any time but to fight the Rebs, please excuse me." After 1863, his letters concern his work as an engineer for the St. Paul and Pacific Railroad and are about family life in St. Paul, Minnesota, with a new wife Emma and sons Irving and Horace Edwin.
In 1862, Horace's brother Irving received a number of letters from his mother, who lived in Roxbury, Massachusetts, and a few from his sister Maria. These concern family affairs and the state of the household, while her sons were at war. Irving Emerson's earliest letter is from April 3, 1863, when he writes from Camp Rogers to his mother and his sister Maria. By 1865, Irving was living in Belfast, [Maine], and was trying to earn his livelihood as a musician. Other family letters include an 1859 letter from Seth Webb to his grandchildren (Maria, Horace and Irving) and an 1864 letter from Amelia's brother Seth Webb, Jr.
Many of the letterheads, such as those dated May 27th, July 26, September 15, and October 6, 1861, have red, white, and blue images of a soldier with an American Flag. A letter from July 4, 1861, contains a large image of the Capitol.
In addition to the letters are four printed items: a monthly report of the Hartford Public High School, with the names of teachers and pupils, including Emma C. Tuttle (1875); and programs for Hartford Public Schools Fourth Musical Festival (1879), the Emerson Chorus concert on November 11, 1879, and the Collinsville Choral Union (1881), all conducted by Irving Emerson.