Henry Hayes Lockwood (August 17, 1814 – December 7, 1899) was an American soldier and academic from Delaware who rose to the rank of Brigadier General during the American Civil War, captured the Delmarva Peninsula including Virginia's Eastern Shore and headed the Union Middle Department in Baltimore before returning to academic life at the U.S.

His ancestor Joseph Lockwood had helped the Patriot cause during the American Revolutionary War by serving on a finance commission and as a member of Delaware's state constitutional convention.

As the American Civil War began, Lockwood entered the Union Army as colonel of the 1st Regiment Delaware Volunteer Infantry.

On November 13, 1861 Major General John A. Dix entrusted Lockwood with capturing the Eastern Shore of Virginia, that is Accomack and Northampton Counties at the Delmarva Peninsula's southern tip.

By massing troops at Pocomoke City, Maryland and promising Virginia residents that if they provided no resistance, their trade would resume, their lighthouses would once again be lit, and their property protected, Lockwood caused the local Confederate forces to retreat and disperse without a fight.

[7] On July 23, 1862, Lockwood commandeered the Cessford estate at Eastville, Virginia (the former residence of the physician serving the Confederate defenders) for his headquarters.

He used it intermittently throughout the war as he led the Union defenses at Point Lookout, Maryland (where the Potomac River enters Chesapeake Bay) and southward on the Delmarva Peninsula.

[9] Corps commander, Maj. Gen. Gouverneur K. Warren, sent the former academic back to the Middle Department because he did not think Lockwood sufficiently competent for so high a rank.

His son James Booth Lockwood, who had been born at the Naval Academy but privately educated, had been commissioned a 2nd lieutenant in the 23rd Infantry in 1873, and spent the following seven years in not only military duties but also surveying, telegraphy and phonography west of the Mississippi River with the U.S. Army Signal Corps.

He volunteered for the Lady Franklin Bay Expedition into the Arctic for the first International Polar Year, but was not among the seven survivors after rescue parties failed.