He was appointed to Annapolis on November 20, 1861, and graduated with the class of 1864, completing his tour aboard the USS America.
From 1864 to 1874, Rear Admiral McCalla was assigned to various boats, including his first assignment aboard the USS Marblehead, before returning to Annapolis as an instructor. He would return to the sea aboard the USS Powhatan in 1878.
While assigned to the Bureau of Navigation, Rear Admiral McCalla led an expeditionary force of 750 men into Panama to aid the Colombian government in saving the city from liberal armies. The force was too late to prevent the burning of Panama City.
In 1887 Rear Admiral McCalla took command of the USS Enterprise, where he would stay until 1890 when he confronted a drunk and disorderly sailor by hitting him with the flat of his sword. Rear Admiral McCalla would be court-martialed and suspended for three years.
When he returned to the Navy, he was assigned to Pearl Harbor Naval Ship Yard before taking command of the USS Marblehead in 1897. While commanding this ship, he would participate in the blockade of Cuba and the severing of Cuba submarine cables during the Spanish-American War,
Rear Admiral McCalla would briefly command the USS Vulcan before taking command of the USS Newark, which he would command through the Philippine Insurrection before leading forces into Peking during the Boxer Rebellion and coordinating units with Sir Edward Seymour during the Battle at Hsiku Arsenal, during the Seymour's 1900 Expedition in China, where Rear Admiral McCalla was also wounded.
Rear Admiral McCalla would return to the US in 1902, taking command of the Naval Yard at Mare Island until he retired on June 19, 1906. He died on May 6, 1910, and rests in Arlington National Cemetery.