Star Trek: 10 Things You Didn’t Know About Jonathan Archer
8. We've Been Talkin' 'Bout Jackson
Star Trek has always pondered over what to call its captains since the very beginning — from Robert April to James Winter (sometimes Spring) to Christopher Pike to James (R or T) Kirk, with plenty more names on that list of possibilities. For the original prequel that dropped the 'Star Trek' from Star Trek until its third season, there was perhaps already a certain degree of certainty - in a way. 'Archer' was shot out to space in and after Broken Bow, but, before any temporal cold war, it's his first name as the extraordinary everyman that was in flux.
The series bible for Enterprise states,
The Kirks and Picards and Janeways will one day have the benefit of the Captains who preceded them. But Jackson Archer is the prototype.
The NX-01 captain was then referred to in the diminutive 'Jack' as late as a revised version of the Broken Bow script dated 11th May 2001, before getting what almost counts as an upgrade to the real thing in the English language as 'Jon[athan]' before filming began.
The reason for the renaming was pretty basic. "It was just a clearance thing," as Scott Bakula told Cinefantastique in October 2001 (Vol. 33, no. 5). At the time, there was only one person in all the United States called 'Jackson Archer,' meaning the name couldn't be used, but there were twenty or more 'Jonathan Archers,' so that one was fine. Later, in the novel Beneath the Raptor's Wing, Archer got the (non-canon) middle name 'Beckett,' and it shouldn't be too much of a leap to see why!