Read this fact today while doing some reading. Found it interesting as it relates to the movie. I thought I would share it with you all.

Days after when the Titanic sank, a body floating was picked up by the Mackay Bennett along the coast of Nova Scotia. The body was identified to be a "J. Dawson." Although not the exact Jack Dawson name as in the movie, Titanic director James Cameron was asked if he knew about this little known fact. Actually, he said he knew about it.
He has also been quoted as going to the gravesite of J. Dawson. Word has it they he already conceptualized the script even before he got hold of the news.

James Dawson is said to be a crewman, working as a trimmer in the coal bunkers and boiler rooms of the doomed ship. His job was to ferry coal from the bunkers to the boiler rooms, and to keep the coal in the bunkers level to maintain the ship's trim. For you landlubbers, "Trim" is a nautcial term that that is to keep the ship from developing a list from uneven loading of the port/starboard coal bunkers).

His body was identified and his family notified. The Dawson family reportedly did not have the funds to pay to have his body to be shipped to his home in England so he is buried in one of the cemetaries in Halifax.