On 15 February, 1864, his gunboat repelled the attack of Confederate raiders, keeping them from saving the town of Waterproof, La., and securing the federal garrison therein. Lt. Johnston resigned from the naval service 23 June 1864 and died 23 April 1912 at St. Louis, Missouri.
On February 15, 1864, Lt. Johnston's gunboat successfully defended Waterproof, Louisiana from Confederate raiders, protecting the town and federal garrison. He resigned from the navy on June 23, 1864, and died in St. Louis, Missouri on April 23, 1912.