Walsh was named after his father's friend, Archbishop John Carroll.
[1][2] Walsh returned to Baltimore in 1840 and purchased "The Mound" and two other farms on Gunpowder River.
[1] In February 1866, Walsh was a member of a convention of Maryland representatives asking the state legislature to appeal or modify voter registration laws for people with Southern sympathies.
[1] He also served as president of the Mutual Fire Insurance Company of Harford County.
[2] Walsh died on December 1, 1894, at his "The Mound" home near Jerusalem Mills, Maryland.