Short answers, pulled from the story.
D. Brainerd Holmes was an American engineer and business executive who directed NASA's crewed spaceflight program from September 1961 to June 1963. During that period he oversaw the Mercury program, including John Glenn's first US orbital spaceflight, and directed planning for Project Gemini and the Apollo program.
Holmes resigned from NASA in June 1963, likely due to tensions with NASA Administrator James E. Webb over the extent of his authority to shape and schedule the space program. He left before the Apollo program reached the moon.
Holmes studied electrical engineering at Cornell University, then worked at Bell Labs, Western Electric, and RCA. At RCA he helped develop the Talos antiaircraft missile, contributed to the electronic systems of the Atlas missile, and was part of the team that built the US Ballistic Missile Early Warning System.
Gilruth wrote that Holmes's management-team approach, in which NASA officials "argued out our different opinions" before a course was set, was essential to the project's success. He stated that "a less skillful leader might have forced an early arbitrary decision that would have made the whole task of getting to the Moon virtually impossible."
Holmes served as president of Raytheon when the company developed the Patriot antiballistic missile system in the 1970s. He is credited with helping shape several of Raytheon's missile programs during his time there before retiring in 1986.
Holmes appeared on the cover of Time magazine on the 10th of August, 1962, as part of the series titled "Reaching For The Moon." The same issue quoted him saying that space is "the future of man" and that the US must keep ahead in it.