It wasn’t until the 19th Century that Calvin’s works were published far enough to gain a wide readership, so after his death there spanned an almost 300 year gap before his modern influence.
In order to explain how Reformed churches and Calvinist churches spread around the world, you have to look at other actors. The total effect of Calvinism came from these ad-hoc, haphazard efforts of churchmen, ministers, leaders in various parts of the world, without any kind of larger organization trying to coordinate them.
