Wadsworth built Hartford House in Geneseo, NY, upon his marriage in 1834 to the former Mary Craig Wharton of Philadelphia.

[3] In 1861, he was a member of the Washington peace conference, an unofficial gathering of Northern and Southern moderates who attempted to avert war.

Despite his complete lack of military experience at the outbreak of the Civil War, Wadsworth was commissioned a major general in the New York state militia in May 1861.

Seeing no prospects for serving in McClellan's army, Wadsworth allowed his name to be put into nomination for governor of New York against antiwar Democrat Horatio Seymour, but he declined to leave active duty to campaign and lost the election.

After McClellan left the Army of the Potomac, and after the serious Union defeat at the Battle of Fredericksburg, Wadsworth was appointed commander of the 1st Division, I Corps on December 27, 1862, replacing Brig.

He made a faltering start in maneuvering his men across the Rappahannock River below Fredericksburg and they ended up being only lightly engaged during the battle.

Arriving in the vanguard of Maj. Gen. John F. Reynolds's I Corps on July 1, 1863, Wadsworth's division bore much of the brunt of the overwhelming Confederate attack that morning and afternoon.

At the start of Lt. Gen. Ulysses S. Grant's 1864 Overland Campaign, Wadsworth led his division in Maj. Gen. Gouverneur K. Warren's V Corps at the Battle of the Wilderness.

Passing Confederate soldiers looted his body of any valuables--John Belote of the 6th Virginia got Wadsworth's pocket watch, which he returned to the general's widow after the war.

Wadsworth was still alive and seen to play with a couple of muskets used to construct a makeshift litter but he did not appear to be aware of his surroundings and attempts to give him food were unsuccessful.

Fort Wadsworth on Staten Island, one of the defenses of New York Harbor, also is named for the general; it is in the shadow of the Verrazano Narrows Bridge.