Public Service:
Johnston was Mayor of Charlotte during the centennial celebration of the Mecklenburg Declaration of Independence, May 20th, 1875.  He served two times as Mayor. Once between 1875 and 1878 and again between 1885 and 1887.

Personal:
Johnston was a planter, lawyer, banker and railroad executive.

During his Administration:
During his first Administration

• Edward Dilworth Latta opened a clothing store in 1876. He later began the Charlotte Consolidated Construction Company (or 4C's). His efforts to develop a trolley system made suburbs possible.
• The town of Huntersville was incorporated.
• St. Peters Hospital (forerunner to Carolinas Medical Center ) opened. It was the first civilian hospital in North Carolina. Located at the corner of Sixth and Popular streets, the building is currently a residential condominium.
• The rail track from Charlotte to Atlanta, Georgia was completed.
• Charlotte's first Chamber of Commerce was organized.

During his second Administration

• Railroad service was opened to Asheville, North Carolina.
• Thompson Orphanage (now the site of St. Mary's Chapel, Thompson Park and the Charlotte- Mecklenburg Vietnam Memorial) was organized by the local Episcopal Church.
• Buford Hotel opened in 1885. It became the home of some of Charlotte's most prominent citizens, including D.A. Tompkins.
• Charlotte got its first female doctor, Annie Alexander.
• Myers Street School became the first grade school for black children in 1886.
• Horse-drawn street cars began operating in downtown Charlotte in 1887.
• The first electric street lights were installed in 1887.