before canals were excavated as short-cuts, the James River shipping channel followed the blue line (Dutch Gap Canal is red line)
Source: ESRI, ArcGIS Online
The first excavation at the site of the future Dutch Gap Canal was made in 1611. Sir Thomas Dale directed colonists to dig a ditch and erect a wooden wall (palisade) there. The ditch was a defensive installation to block Native American attack, not for transportation. After isolating the peninsula, the colonists built Henricus there to replace Jamestown.1
in 1611, Sir Thomas Dale had colonists excavate a ditch at the future site of the Dutch Gap Canal
Source: Thomas Jefferson Wertenbaker, Virginia Under the Stuarts, 1607-1688 (p.20)
The first effort to build a transportation canal at Dutch Gap occurred during the Civil War.
At the start of the 1862 Peninsula Campaign, Confederates were forced to abandon Norfolk and destroy the C.S.S. Virginia ironclad. To block the Union Navy from steaming up the James River and besieging Richmond, the Confederates fortified Drewry's Bluff and sank vessels in the river. The Union forces could not force their way past the Confederate line of defense, or bypass it.
In 1864, General Ulysses S. Grant led Union forces south on the Overland Campaign. Heavy losses outside Richmond at Cold Harbor made clear that he could not break through the Confederate trenches protecting the Confederate capital. He pivoted south of the James River and tried to capture Petersburg. Control of the railroads which passed through that city would allow Grant to cut off the supplies needed by the Confederate capital. The Army of Northern Virginia would be forced to move away from its prepared defenses, exposing General Robert E. Lee to much higher risk of defeat and capture.
Grant assigned General Benjamin Butler and his Army of the James the responsibility for landing on the Bermuda Hundred peninsula and advancing west to cut the Richmond and Pettersburg Railroad, north of the Appomattox River. Confederate defenders reacted quickly and blocked his advance. Their defensive line, known as the Howlett Line, trapped the Army of the James like a "cork in the bottle" for the rest of the war.
General Butler tried to bypass the defenses, such as Battery Dantzler on the James River shoreline, using a technique used by General Grant at Vicksburg. He planned to dig a canal at Dutch Gap, allowing US Navy gunboats to get around the northern end of the Howlett Line.2
the canal at Dutch Gap was designed by Union Army engineers and excavated by black men
Source: Library of Congress, Dutch Gap Canal commencement of the work
The gunboats required a channel that was at least eight feet deep. The bend of the James River upstream of Butler's line, curving around Farrah's Island, was only four feet deep. A canal would allow the gunboats to support a landing of Union troops, though the time required to dig the channel eliminated any opportunity for surprising the Confederates before they adjuted their defense line.
African-American soldiers in several US Colorerd Troops regiments were given the task.3
General Butler sought to bypass Confederate defenses along the James River by cutting a canal at Dutch Gap
Source: Library of Congress, Map of operations at Bermuda Hundred and Drewry's Bluff, Virginia, 10th May 1864 (by Robert Knox Sneden)
The Union Army forced local men who had formerly been enslaved to dig the canal. The laborers were rounded up at the point of a bayonet and required to work without pay. Years later, a paleobotanist would examine a fossil found in the walls of their ditch and identify one of the earliest flowering plants in Virginia. In 2013 he named the species of plant Potomacapnos apeleutheron. The species name "apeleutheron" was the Greek word for freedmen. The scientist explained:4
Butler's efforts failed, in part because human laborers and steam dredges were not powerful enough to excavate the hard mud at Dutch Gap. In January, 1865, the last remaining wall of dirt was blasted away, but it quickly became clear that the excavated channel was too shallow to permit Union gunboats to sail upstream. When Richmond was finally occupied by the Union in April, 1865, warships steamed past abandoned Confederate fortifications rather than through the Dutch Gap Canal.
the Union planned to cut a Dutch Gap Canal (red lines) through one bend in the James River in 1864, but the 1878 canal cut through two bends
Source: Virginia Department of Historic Resources, The Richmond Ironclads at Trent's Reach, James River
digging the Dutch Gap Canal was a physically-exhausting job
Source: HathiTrust, Harper's Weekly, General Butler's Canal At Dutch Gap (November 5, 1864, p.712)
ships had to navigate around three bends in the James River, before canals cut through them after the Civil War
Source: Library of Congress, Map of part of Henrico and Chesterfield Counties, July 12th, 1862 (by Albert H. Campbell, ~1862)
view from James River of Dutch Gap Canal
Source: National Archives, Virginia - Dutch Gap Canal (1933 or earlier)
Dutch Gap Canal
Source: National Archives, Virginia - Dutch Gap Canal (1933 or earlier)