Harry Hamilton Laughlin, a son of George Hamilton and Deborah Jane Laughlin, was born at Oskaloosa, Iowa, on March 11, 1880, and spent his youth in Kirksville, Missouri. His father was a minister of the Christian Church in Kirksville and professor of Romance Languages at the First District Normal School (now Truman State University).

Laughlin attended the schools in Kirksville and graduated from the First District Normal School in 1900 and served the Kirksville High School first as a teacher and later as principal. In 1903 he went to Centerville, Iowa, as the high school principal. Laughlin returned to Kirksville in 1905 to assume the superintendency of the Kirksville schools. He taught agriculture at the First District Normal School from 1907 until 1910.

In February 1907, Laughlin's interest in breeding experiments led him to write Charles Benedict Davenport, the director of the Station for Experimental Evolution at Cold Spring Harbor, New York. Dr. Davenport was one of the first scientists to introduce the concepts of Mendelian genetics into the United States. After establishing the Eugenics Record Office, underwritten by Mary (Mrs. E.H.) Harriman, Davenport asked Laughlin to be the superintendent. In October 1910, Laughlin and his wife Pansy moved to Cold Spring Harbor, New York where they stayed for the next 29 years. Dr. Laughlin received a D.Sc. from Princeton in 1917 for a thesis on cytology and an honorary degree from the University of Heidelberg in Germany in 1936.

He was superintendent in charge of the Eugenics Record Office of the Department of Genetics of the Carnegie Institute of Washington, D.C., from its origin in 1910 until 1921, and director from 1921 until 1940. Laughlin served as the eugenics expert for the Committee on Immigration and Naturalization, United States House of Representatives from 1921 to 1931; the Eugenics Associate to the Municipal Court at Chicago, 1921 to 1930; the United States immigration agent to Europe for the Department of Labor from 1923 to 1924; and was a member of the permanent Immigration Commission of the International Labor Office of the League of Nations in 1925. He also was a member of the Galton Society, the Eugenics Research Association, the American Society of International Law, the American Statistical Associate, president of the American Eugenics Society 1927-28, associate editor of the Eugenical News from 1916 to 1939, secretary of the Third International Congress of Eugenics in 1932, and president of the Pioneer Fund, Incorporated, from its origin until 1941.

Laughlin was a prolific writer, publishing numerous articles and books on eugenics, eugenical sterilization, immigration, genetics, and various phases of inheritance including racing capacity in thoroughbred horses. It is his work on eugenical sterilization and immigration restriction for which he is best known. Laughlin's Eugenical Sterilization in the United States established him as an expert on the topic. His model sterilization laws were used by many of the more than 30 states that passed sterilization laws. Germany's 1933 sterilization laws were also modeled after Laughlin's. Laughlin's immigration studies, which seemed to support the idea that recent immigrants from Southern and Eastern Europe had a higher percentage of "socially inadequate" persons than other immigrants, led to the highly restrictive immigration quota system of 1924 which favored immigrants from Northern Europe. As is evident from the collection, Laughlin also devoted considerable time and effort developing his ideas for a common world government.

Laughlin married Pansy Bowen of Kirksville on Sept. 13, 1902; they had no children. After his retirement from the Eugenics Record Office, they returned to Kirksville in December 1939. Dr. Laughlin died January 26, 1943, and was buried near his father and mother in Highland Park Cemetery in Kirksville.