As a Virginian who stood for the Union Army, Craighill was division and department engineer during the American Civil War and worked on the defenses of Pittsburgh, Baltimore, San Francisco, and New York City.

After the Civil War, Craighill superintended construction of defenses at Baltimore Harbor and Hampton Roads.

He headed the Engineer Office in Baltimore from 1870 to 1895, overseeing river and harbor work in Maryland and parts of Virginia and North Carolina.

When the Corps began to build locks and dams on the Kanawha River in West Virginia in 1875, Craighill assumed charge there as well.

He completed the first of the moveable wicket dams built in the United States, after visiting France to study their use.