[8] At the start of the U.S. Civil War, he returned to serve in the Union Army and was commissioned a captain in the 54th New York Volunteer Infantry.

In 1864, he was promoted lieutenant colonel and commanded the 2nd United States Colored Cavalry Regiment in actions through Virginia.

[8] On August January 15, 1865, he led the assault on Fort Fisher in Virginia, which captured the Confederate post for the Union.

[11][12] The subsequent sensation caused Van den Nest to lose his position, forced Lawrence to resign his post, and effectively ended the marriage of Albert and Eva.

[14] In his editorial, The New York Times stated that his endorsement meant that "The Democrats are mortified at the spectacle of a son of the sage of Ochre Point coming out so publicly for Garfield and Arthur.

[11][13] Before their public divorce in 1879,[11] they were the parents of:[15] Lawrence died at the Everett House in New York City on January 1, 1887.