Current 4 stroke Mercurys are Tohatsu up to 30 hp. 40, 50, 60 are Mercury designs now made in China. (sad) 75 hp and higher are all Verado based (75, 90, 115 naturally aspirated without digital throttle and shift) and built in Fond du Lac, Wisconsin. Opti Max 2 cycles are all built in Fon du Lac. Many of the sub assemblies and components come from Mexico and beyond. It is very difficult to find anything that is truly produced in one country anymore.
Hope this helps,
Randy