Short answers, pulled from the story.
Francis Amasa Walker entered the world on the 2nd of July 1840, in a prominent family home in Boston. The Walkers lived next door to Oliver Wendell Holmes Sr., making Francis and Oliver Jr. playmates during their early childhood years before moving to North Brookfield, Massachusetts in 1843.
Walker assumed an appointment as sergeant major on the 1st of August 1861, before being reassigned as assistant adjutant general to brigadier general Darius N. Couch and promoted to captain by September 14. He remained in Washington, D.C., over the winter of 1861, 62 and did not see combat until May 1862 at the Battle of Williamsburg.
The 1870 census proceeded under rules governing previous collections, which Walker deemed inefficient and unscientific while lacking authority to determine personnel or methods. This work culminated in publication of the first Statistical Atlas of the United States, which won praise from the secretary of the Smithsonian Institution and earned a first-class medal from the International Geographical Congress.
Walker was strong believer in social Darwinism, eugenics, and immigration restriction with theories foundational for modern American nativist movement. His reputation declined in 21st century due to espousal of racist views in general and on Native Americans in particular leading to removal of his bronze bust from MIT in 2022.
Walker served as professor of political economy at Yale before accepting appointment as president of Massachusetts Institute of Technology in June 1881. He formally elected by MIT Corporation the 25th of May 1881, resigning from Yale in June and 1880 census in November to lead the institution until his death in 1897.