Apart from John C Pemberton were there any other Northerners who became Confederate Generals?

Answer 1

The highest ranking Confederate General of all was from New Jersey. His name was Samuel Cooper and few people have heard of him today. He had married a girl from Virginia and went south with her when secession came. He had been Adjutant and Inspector General of the US Army when Jefferson Davis was Secretary of War during the Pierce Administration. As Confederate President, Davis named him to the same position in the new Confederate Army. In the summer of 1861 the Confederate Congress passed an Act authorizing the promotion of five officers to the rank of full, four star general. In August Davis submitted his list, in order of the seniority they were to have at this rank - Cooper, Albert Sidney Johnston, Robert E. Lee, Joseph E. Johnston and Pierre G. T. Beauregard. Davis seems to have hoped Cooper would help him manage the Confederate war effort, but Davis had the tendency to micromanage and was usually dissatisfied with anything anybody else did. This attitude plus Cooper's own reluctance made Cooper basically a glorified clerk, despite his exalted rank. He never held a field command for the Confederacy.

The New York City Street Department seems to have been a hotbed of Confederate sympathy. The Street Commissioner in 1861, Gustavus W. Smith, was a West Pointer born in Kentucky. He went south and became a Major General. Serving with Smith on the NY City Street Commission was Mansfield Lovell, another West Pointer, born in the District of Columbia. He also became a Confederate two star.

Bushrod R. Johnson was a West Pointer and a Confederate two star from Ohio.

Daniel M. Frost was a West Pointer from New York who became a Confederate one star.

There were a few others but I'm not remembering them right now. There were about 423 men generally agreed to have been a one, two, three or four star Confederate general, and almost all of them were from the south. Only two foreign born individuals got two star rank.