Jerome did not specifically make an official acknowledgement to any particular person on the three men in a boat. But he did mentioned that he got the inspiration and the materials for this book from his honeymoon trip in 1888. Hope this helps
The
novel was about a boat trip that the narrator took to thames river
along with his friends. He goes on rambling about the trip and takes
the time to digress or go off topic to tell anecdotes. What was
really memorable about the book was the places visited which were
described beautifully.
Apparently
Jerome got the inspiration from one of his trip to the thames for his
honeymoon in 1888, and his experiences provided him the subject
material for the novel.
