He is most remembered today for his involuntary participation in John Brown's raid on Harpers Ferry, Virginia, in 1859.

As he outranked the other hostages, he was their unofficial spokesperson and testified in both Brown's subsequent trial and before the Senate committee investigating the raid.

Ultimately, Washington and the others were held at Brown's base in the fire engine house of the Harpers Ferry federal arsenal.

[4] During John Brown's trial for treason against the Commonwealth of Virginia, Lewis Washington testified as a witness for the prosecution.

During cross-examination, Washington testified that Brown treated his hostages well and gave orders not to harm civilians.