How does Irving develop Ichabod Crane into a round character in "The Legend of Sleepy Hollow"?

Round characters increase in development and complexity as a literary work progresses, and this is true of Irving's characterization of Ichabod Crane.

In the story's exposition, Crane is described as an exacting schoolmaster who metes out punishment to recalcitrant students in the belief that they will one day "remember it, and thank him for it." He lives as an itinerant educator, boarding for weeks at a time with the families of his students and eating voraciously, though remaining exceedingly thin. He's a bit of a hustler, ingratiating himself with families by helping on their farms, helping to care for their children, and offering singing lessons, as well. The narrator deems him "an odd mixture of small shrewdness and simple credulity" and notes his belief in witches after reading the works of Cotton Mather as well as his fondness for the ghost stories the Dutch housewives tell him.

Ichabod sets his sights on Katrina Van Tassel once he sees her beauty, and more importantly, the bounty of her family's farm. He becomes increasingly greedy in his thinking of how he will marry her, sell the land she inherits, and set off with their children "for Kentucky, Tennessee, or the Lord knows where."

When Brom Bones becomes his rival for the hand of Katrina, Ichabod Crane does not flinch. The narrator describes him in this way:

He had, however, a happy mixture of pliability and perseverance in his nature; he was in form and spirit like a supple-jack—yielding, but tough; though he bent, he never broke; and though he bowed beneath the slightest pressure, yet, the moment it was away—jerk! he was as erect, and carried his head as high as ever.

Though Brom Bones is more robustly endowed and equally determined to marry Katrina, Ichabod doggedly continues his pursuit of the woman he sees as an heiress. He behaves as a sort of anti-Brom in that his approach is "a quiet and gently-insinuating manner" while Brom is much more direct.

After enduring the practical jokes of Brom Bones that make him sometimes question his own sanity, Ichabod is bested by his rival. Despite his intelligence, education, and social adeptness, Ichabod is no match for the apparent supernatural terror the Headless Horseman presents. His persistent courting of Katrina comes to an abrupt end, and he is never seen again.

How does Irving parody Ichabod Crane as a "Romantic hero" in "The Legend of Sleepy Hollow"?

Ichabod Crane is shown to be VERY enamored of Katrina Van Tassel...her wealth, that is! When most Romantic heroes would be writing poetry to her beauty, her grace, her style, her modesty, etc., Ichabod is far more excited by her father's land and wealth, and all of the wonderful food that is served in their house. The food, in fact, is truly the impetus behind his passion for the fair Katrina!

In addition, a Romantic hero would not have allowed the superstitions and ghost stories of Brom Bones to sway him in his courting of Katrina. He would have braved all kinds of threats to remain in the village of Sleepy Hollow and continue his pursuit of Katrina('s wealth). And yet he lets his imagination run wild with him and turns tail and runs when he thinks the Headless Horseman is after him. Not exactly the picture of a Romantic hero, is he?

This ironic parody of the Romantic hero is one of Washington Irving's most skillful characterizations. Check the links below for more information - Good luck!