I found Arthur G. Smith in two 1940 US Census. One is 52y and the other is 22y old. The older one is divorced and in Ward 7, Minneapolis City, Hennepin Minnesota. He was born in IL, and father-in-law to the Recitte's. Horton Recitte, head is 27, wife Dorothy is 23, dau. Beverly is 6, son James is 3 and daughter Janette Recitte is 1.
The other 1940 US Census (maybe the older Arthur G. Smith's son) was born in MN and is 22 years old, living with his wife Laura also 22. Two children, Laurel is 1 and Paul is 0, so he must be a new born baby.
1930 US Census has Arthur G. Smith 41y, b. IL, wife Nellie 31y, b. Holland. Head of household Challen M. Jones 28 b. MN, his wife, Elinore M. 24y b. IL and roomer Swanberg 18y b. MN.