When I first became involved in the ISA (now International Society of Automation), it was already facing a major challenge. It's name was then the Instrumentation Society of America, but not only was it rapidly being pushed into international engagement, but the field of instrumentation was undergoing such dramatic change that computers and software were becoming the pivotal technologies in automation.
The name change hints at some of the internal and programmatic changes that were required of the organization, but it also faced financial challenges. I served for a while on the board of ISA Services, a for-profit subsidiary of ISA, which at the time generated substantial funding (around $20 million annually, as I recall) for the organization through a massive trade show and several print publications that carried advertising.
Needless to say, these activities suffered shocks with the advent of the Internet and related changes in the way people receive information.
ISA, as with virtually all professional societies, has had to reinvent itself through this period, most recently culminating in their new strategic direction. You can read (and hear) more about it on their website, featuring three short videos by their Executive Director, Mary Ramsey: