“Thousands” seems like a pretty big stretch! We have no idea how many people he employed, nor how “endless” his charitable contributions were. However, all sources indicate that just as in Milford, Brinkley was indeed responsible for bringing some prosperity to the region, and that he engaged in charitable activities.
References
"[Brinkley] maintained a pay roll estimated at between $17,000 and $20,000 [in Del Rio] . . . he thought the high school should have a business course and donated the desks, typewriters and other equipment. He provides candy and fruit for every child in Del Rio at a Christmas party each season. When the Rotary Club sought to increase its student loan fund, he offered to match it . . . He offered $25,000 cash if the city would cause a similar amount for a public library to be raised" ("The Case of Brinkley v. Fishbein", Journal of the American Medical Association, May 13, 1939, Volume 112, No. 19, p. 1952).