Is Sonic the Hedgehog american

Answer 1

It is somewhat difficult to tell. The character was created in Japan but a great deal of the games were produced in America.

If you are talking about in universe then no he is not. Depending on the continuity Sonic is either from Mobius or Earth (and I believe there are some others). In the earth continuity it appears that Sonic is from a country based on America as it has a president and appears to be in a building similar to the white house. This country is not America, simply similar.