SB-1 “Detroiter” first flew on 25 January 1926 on a demonstration flight from Selfridge, MI.  It was a streamlined, fully enclosed cabin biplane with seating for 4 and was initially powered by a Wright Whirlwind J4, 9 cylinder, 788 cu in engine developing around 215 to 220 hp, it was the first Wright engine to use the “Whirlwind” moniker.  

The success of the SB-1 allowed for Stinson to secure the capital necessary to incorporate the Stinson Aircraft Corporation on 4 May 1926 and acquire his first production facility at Northville, MI later that year.

10 March 1926 photo. This was the prototype SB-1. Note the fabric covered cabin interplane struts and the different empennage design
Much better view of the early empennage design. This was changed in August 1926 when production of the airplane began at the Northville, MI facility.
Great view of the tire chains used to demonstrate the airplanes wheel brakes and control on slippery surfaces
serial number 1, NC872. Built in October 1926 and delivered to Northwest Airlines. A promotional photo: from left to right: David Behncke, William Kidder, James Lincoln, Mrs. George Leach (Detroit Mayors wife), and William Stout christening the first SB-1.
The SB-1 interior as it appeared in an advertisement for the airplane in the 20’s
On skiis at Wold-Chamberlain air field, Minneapolis, MN (Photo from Tom Wier)
Northwest Airways NC872. Serial Number 1. Northwest provided the first “scheduled” passenger service in an enclosed cabin with this airplane.
Front view of NC852 on ski’s. (Photo from Tom Wier)
Possibly when owned by Wien Alaska.
Built in Jan 1927 this airplane was the former Wilkins Expedition the “Detroit News”. Noel Wien purchased the airplane from George H. Wilkins in Sep 1927 and merely changed the name on the fuselage, leaving the left hand under wing titling intact. At the time of Wien’s purchase, it was equipped with a 200 hp Wright J4-B engine, serial number 7250.
At Candle AK, 1927. A 35 mph wind packed the engine with snow under an engine cover
Built in 1927 as NC3707. It was sold to Canada and had two registrations. One was C-CAGF, and C-CANI. It was operated by Purple Label Airlines which was soon taken over by Great Western Airways. The airplane crashed at Cochrane, Alberta on 19 Jul 1934 after an engine failure on take-off.
Serial Number 104. Note the difference in empennage design as compared to the prototype SB-1. It was initially registered as NC3708 before it went to Canada and became C-CAJC with Patricia Airways & Exploration, Ltd.
Florida Airways “Miss Atlanta” operating on C.A.M. Route 10