A is for Archer. Jonathan Archer. Legendary explorer and early President of the young Federation from 2184 until 2192.
B is for B(ar)oner. Pseudonym used by Captain Kirk during the Klingon occupation of Organia in 2267.
C is for Cochrane comma Zefram. He made us go.
D is for Dick Daystrom. Inventor of the Duotronic computer system.