Some may know, others probably don't but what was the very first year they began producing trucks?

1908 Buick Truck?

This 1908 truck is one of a handful of double-chain-drive Buicks known to exist. It was used for light delivery in the Madison/Skowhegan, Maine area.

Specifications: engine two-cylinder opposed, air-cooled; bore 4-1/2 in., stroke 5 in., displacement 159 cu. in., 22 hp.

I am looking for the first truck that was made under the "General Motors" monikor that Durant established in 1908. First it was cars, then trucks came on under the GM "company" i guess you could say.

Then you must be referring to GMC in 1912?

GM bought the Rapid & Reliable independant manufacturers in 1908-1909- so this would be concurrent with the Buick truck (I have not been able to verify which make was bought which year- my sources disagree).