I believe, so the story goes, the civilian test pilot was holding out for more money, so Chuck got to be the first super-sonic. While he probably knew there would be fame and glory, mostly, I think, he did it from a sense of duty, honor and adventure.
Ran across him twice. 1st was Edwards during the C5 testing. We had a number of celebrities visit the C5, but since it flew all day, literally airborne from 8am til 5pm with an engine running crew change at noon, visits were generally at night. I worked the night shift recovering the a/c and prepping them for the next days flights. Chuck was one of the visitors. And as with most pilots they wanted to know about the flying characteristics. I generally got to discuss the avionics with the visitors. With Chuck however several pilots had hung around. I stood in the back of the cockpit and did get to handle one or two questions about the auto-pilot and power steering systems.
2nd time was at the NRA Annual meeting in Orlando a while back. Didn't get to meet with him, but thoroughly enjoyed his speech. He started by saying they told him to talk about hunting and fishing, but said he had told so many "tall tales" he wasn't sure what was fact and what was fiction anymore. Wanted to know if the crowd would rather hear him talk about flying. The crowd went wild. The stories were funny and fascinating.
A true legend.