The Wabash bought 63 "Mikado" type locomotives in 1912 and designated them as Class K-1. The railroad split the order between the Baldwin Locomotive Works, which delivered 28 and the American Locomotive Company, which delivered 15 from its Richmond Locomotive Works and 20 from its Pittsburgh Locomotive & Car Works.

A group of 20 more ALCO-built USRA Light, 2-8-2s arrived in 1918. They were designated Class K-2. In 1919, five of these locomotives were transferred to the Pere Marquette and five Baldwin-built 2-8-2 locomotives were moved from the Western Pacific to take their place. USRA 2-8-2s were specified to have 63" diameter drivers. The Wabash listed these locomotives as having 64" diameter drivers because it is believed that they were refitted with thicker tires. The Class K-2s had 26" x 30" cylinders, a 200 psi boiler pressure, a 54,600 lbs tractive effort and the locomotive, without a tender, weighed 290,800 pounds.

In 1923, ALCO shipped 30 "Mikado" type locomotives to the Wabash. Five of them were equipped with boosters, which increased the locomotive weight by 10,000 pounds and the tractive effort by 11,836 pounds. The 25 without boosters were designated as Class K-3 and the five with the boosters were designated Class K-3b. These locomotives had 64" diameter drivers, 27" x 32" cylinders, a boiler pressure of 210 psi, and a tractive effort, without the booster, of 65,063 pounds. The locomotive without a tender weighed 325,000 pounds (numbers 2250- 2269) and 331,000 pounds (numbers 2270-2279).

The Wabash received another 45 ALCO-built "Mikado" locomotives in 1925, with 20 of them equipped with boosters, which were very similar to the boosters furnished on the class K-3b locomotives. The group with the boosters was designated as Class K-4b and assigned road numbers 2700-2719. The locomotives without the booster was designated as Class K-4 and assigned numbers 2720-2744. These locomotives had 64" diameter drivers, 27" x 32" cylinders, a boiler pressure of 210 psi and a tractive effort of 65,063 lbs without the booster. They weighed 333,730 pounds (numbers 2730-2744) and 338,580 pounds (numbers 2700-2729) without a tender or the booster. Number 2743 and 2744 were used to build a pair of Class P-1, 4-6-4 locomotives in 1947 and 1948. These "Hudson" type locomotives were built in the Decatur Shops of the Wabash.

The last new 2-8-2 locomotives to be added to the Wabash roster were five ALCO-built 3 cylinder "Mikado" type locomotives which were delivered in 1925 and designated as Class K-5. They had two 23" x 32" cylinders and one 23" x 28" cylinder, 64" dia. drivers, a 210 psi boiler pressure, a tractive effort of 67,869 pounds and the locomotive without a tender weighed 340,490 pounds. These five locomotives did not perform as well as expected and were put into storage shortly after their arrival. In 1943 and 1944 the boilers from these locomotives were used in 5 of the Class P-1 "Hudson" locomotives (road numbers 700-704) built in the Decatur Shops.

There are no surviving Wabash 2-8-2 Mikado type locomotives.