Ichabod Crane, a lanky, credulous Connecticut schoolmaster with an enormous appetite, teaches psalmody in a drowsy Dutch valley on the Hudson and courts Katrina Van Tassel, or really her father's fat acres, against Brom Bones, the local strongman who rides a horse called Daredevil. Riding home from a quilting frolic at the Van Tassel farm, Ichabod meets the valley's household bogey: a Hessian trooper on horseback who lost his head to a cannon-ball. Know going in that this is barely a ghost story. Irving spends most of it on Dutch cake, mock-heroic digression and Ichabod's own gullibility, and the horseman does not turn up until the final sixth.
The Legend of Sleepy Hollow is 12,161 words. At an average adult reading pace of 300 words a minute that is about 41 min, or roughly 30 min if you read quickly and 1 hr 1 min at a more deliberate 200 words a minute.
That count is measured from the complete public-domain text rather than estimated from a page count, so you can compare all the books side by side.