The most relevant sentences to include in a summary of the text are:
- "John Fitch combined old methods of constructing boats with new technology to create the first steamboats."
- "It wasn’t until after his death that Robert Fulton created a commercially successful steamboat and became known as 'the father of steam navigation.'"
These sentences capture the main points regarding Fitch's contributions to steamboat invention and the subsequent recognition of Robert Fulton. The sentence about the cost of Fitch's boats is also relevant but less comprehensive than the other two. The statement about riding on a steamboat is not pertinent to the summary.