He had engineering skills that were genuinely valuable to a military force conducting sieges and building fortifications.

He was educated, experienced, multilingual, and physically capable.

By any rational assessment of the qualities the army needed, he was a strong candidate for a commission.

He was rejected.

The Secretary of War’s office informed him that commissions were available to citizens of the United States, and that the question of his citizenship was not considered resolved in his favor.

Parker tried multiple times and through multiple channels.