The secondary battery consisted of twenty-one /51 caliber guns mounted in casemates along the side of the hull. The main armored belt was thick, while the gun turrets had thick faces. The conning tower had thick sides. In 1925, "Arkansas" was modernized in the Philadelphia Navy Yard. Her displacement increased significantly, to standard and full load. Her beam was widened to , primarily from the installation of anti-torpedo bulges, and draft increased to . Her twelve coal-fired boilers were replaced with four White-Forster oil-fired boilers that had been intended for the ships cancelled under the terms of the Washington Naval Treaty; performance remained the same as the older boilers. The ship's deck armor was strengthened by the addition of of armor to the second deck between the end barbettes, plus of armor on the third deck on the bow and stern. The deck armor over the engines and boilers was increased by and , respectively. Five of the 5-inch guns were removed and eight /50 caliber anti-aircraft guns were installed. The mainmast was removed to provide space for an aircraft catapult mounted on the Number 3 turret amidships. "Arkansas" was laid down on 25 January 1910, at New York Shipbuilding in Camden, New Jersey. She was launched on 14 January 1911, after which fitting-out work was effected. The ship was completed by September 1912, and was commissioned into the US Navy on 17 September, at the Philadelphia Navy Yard, under the command of Captain Roy C. Smith. Following her commissioning, "Arkansas" participated in a fleet review on 14 October 1912, for President William Howard Taft. The ship took Taft aboard that day for a trip to Panama to inspect the Panama Canal, which was still under construction. "Arkansas" began her shakedown cruise after delivering Taft and his entourage to the Canal Zone. During this cruise, the Navy's first long-distance, continuous-wave, wireless telegraphy system was successfully tested, with regular transmissions received by "Arkansas" from a prototype Poulsen-arc transmission facility located in Arlington, Virginia. On 26 December, she returned to the Canal Zone to take Taft to Key West, Florida. After completing the voyage, "Arkansas" was assigned to the Atlantic Fleet and participated in fleet maneuvers off the east coast of the United States. "Arkansas"s first overseas cruise, to the Mediterranean Sea, began in late October 1913. While there, she stopped in several ports, including Naples, Italy on 11 November, where the ship celebrated the birthday of King Victor Emmanuel III of Italy.