The British developed the Canberra as a replacement for the Mosquito. The plane was so successful that the US purchased the license to build it to fit their needs. After some cockpit modifications along with a few others, the B-57B was born.
I have a personal relationship with this plane in that my Dad worked on the Electronic Countermeasures version at both Westover AFB and Malmstrom AFB so I got to see a lot of these flying around and have loved the plane ever since.