Constable's first drawing of this subject shows a barge emerging from trees, balanced by a horse and a sluice-gate, but with no leap at all: the horse stands patiently at the barrier while its rider looks back toward the barge, its posture calm and its outline echoing the bend of a nearby osier tree and a stretch of cloud above it^[1]. The dramatic leap first appears in a later chalk and sepia drawing, and its arrival transforms the whole design: the clouds rise, the timber buttress supporting the sluice gains an upward thrust, the barge is pushed forward more forcefully, and the osier straightens, every element of the composition suddenly working together around the horse's motion^[1].

Constable made a full-size preparatory study for the composition before painting the finished canvas he sent to the Royal Academy in 1825. The study, now held in the Victoria and Albert Museum, is worked in stormy, forceful strokes of the palette knife that leave the whole surface feeling alive and unresolved, while the exhibited picture is calmer, more graceful in its drawing of the trees and more firmly finished in its distant view of Dedham church tower^[1]. Constable had not originally intended the full-size study to stand as an independent work; the practice grew out of his difficulty translating the intensity of a small sketch onto the scale of his largest exhibition canvases, which he and later writers came to call his six-footers, and once he adopted the method for his first large canvas he kept using it for his major landscapes from then on^[1].

One small element of the composition, an osier tree to the right of the horse, caused Constable persistent difficulty as he reworked the picture. When the tree rose in visual sympathy with the leaping horse, it became too dominant a feature in the design; when he restored it to its position from the earliest sketch in the Victoria and Albert study, it instead constrained the horse's movement^[1]. The tree was still positioned to the right when the finished picture went to the Academy in 1825, and only after it returned to Constable unsold did he move it into its present central position, a change that forced him to slow the pace of the barge behind it, remove the figure of the man punting the barge, and repaint the barge's prow so that it no longer thrust forward out of the trees but lay parallel to the riverbank^[1].