I highly recommend Jon Bois' Youtube docuseries[1] on this story that's basically a 4-hour PowerPoint presentation which frames this all through the metaphor of the 90s Tim Allen sitcom Home Improvement. That descriptor probably sounds insane to anyone not familiar with his work, but Bois is one of a kind with what he does and I thought this series was one of his best.

[1] - https://www.youtube.com/watch?v=zmyBSrQodnI

I just finished reading this book, which came out this year.

Lightning Beneath the Sea: The Race to Wire the World and the Dawn of the Information Age by James M. Tabor (Author)

About this telegraph cable, and all of the different attempts to lay it on the sea floor.

I also recommend The Victorian Internet by Tom Standage (1998) if you want to learn more about telegraphs.