Gilfillian was born on March 9, 1829, in
Bannockburn,
Scotland. His parents emigrated to the United States when he was young and settled in
Oneida County, New York. He studied law in
Chenango County, New York, and
Ballston Spa, New York, and was admitted to the bar in 1850. After continuing to study law in
Buffalo, New York, for a few years, he decided to relocate to
St. Paul, Minnesota, in 1857. He opened a law firm with his brother,
Charles Duncan Gilfillan, though the
American Civil War brought their partnership to an end. Gilfillian served with the
7th Minnesota Volunteer Infantry Regiment and was later named the colonel of the
11th Minnesota Volunteer Infantry Regiment. After the war ended, he returned to St. Paul to pursue a career in law. When Chief Justice
Thomas Wilson resigned from the Minnesota Supreme Court in 1869, Gilfillian was named his interim replacement him by Governor
William Rainey Marshall. When Chief Justice
Samuel J. R. McMillan resigned in 1875, Gilfillian was again named as an interim replacement by Governor
Cushman Kellogg Davis. This time he stood for re-election and won. He served on the Minnesota Supreme Court until his death in 1894. ==References==