The Martin B-10, which first flew in prototype form in '32, went into service with the USAAF in summer of 1935. It was a sales success, with the US government buying over a hundred and export sales to China, the Dutch, Thailand, and Turkey.
We phased ours out pretty quickly at the start of WW2, but the type saw extensive combat with the Chinese, Dutch, and Thai forces, and Thailand didn't retire theirs until 1949.
It was replaced as a frontline aircraft in the USAAF inventory by the Douglas B-18 Bolo.
