Soo Line #552 was built as a mail car by Barney & Smith Car Co. in April 1906. It was the second car numbered 552 on the Soo Line since the first #552 was destroyed. The car is of all wood construction and was built having steam heat and oil lamps. Car 552 remained as a mail car until July 1919 when it was rebuilt at the North Fond du Lac Shops into milk car #650. By April 1930 the car was converted at the Shoreham Shops to combination mail and express car #511. Most of the car was for express while a smaller portion (15 ft.) was for mail. The car had a vapor heating system and electric lights. The #511 was assigned as a trailer behind the Soo Line’s gas-electric car M-1 and was used between Gladstone and Sault Ste. Marie, Michigan, on trains No. 86 and 87. On May 23, 1942, the car was converted to a cook and bunk car and renumbered X-1428. As a work car it was last used by the Soo Line as a locker room in Schiller Park, Illinois, following a 1977 tornado which destroyed the car shops. The car was purchased and moved to Mid-Continent in August 1982. Currently painted as work car X-1428, it is awaiting restoration to its original condition.

Articles of Incorporation for the Minneapolis Sault Ste. Marie & Atlantic Railway (commonly known as Soo Line) were filed in Madison, Wisconsin on September 29, 1883, by several Minneapolis businessmen. Their goal was to link the flour mills of the Twin Cities with the Great Lakes shipping port of Sault Ste. Marie. By the end of 1887, the line was completed across the northern part of Wisconsin to reach the road’s namesake. The next 25 years saw much expansion and consolidation with other smaller roads. The Wisconsin Central was leased in 1909; in 1961, it was formally absorbed as well as the DSS&A to form the new Soo Line Railroad. Soo Line successfully purchased the remains of the Milwaukee Road in 1985, forever changing its system map; two years later, the new Wisconsin Central Ltd. purchased the old WC route and other track from Soo Line. Today the Soo Line exists only on paper, under the Canadian Pacific banner, most of its original trackage now operated by other companies or abandoned.