If you mean "American" as in someone born in the Americas, yes. If you mean "American" as in a US citizen, no; they are Mexican, unless one of their parents is American.
La Sirenita was born in Matamoros, in Tamaulipas, Mexico.
Carlos Cobos was born on December 10, 1958, in Matamoros, Tamaulipas, Mexico.
Rigo Tovar was born on March 29, 1946, in Matamoros, Tamaulipas, Mexico.
Amalia Matamoros was born in 1989.
Horacio Pina was born March 12, 1945, in Matamoros, Coahuila, Mexico.
Rubén Matamoros was born on 1982-08-19.
Lucía Matamoros was born on 1984-12-08.
Hólger Matamoros was born on 1985-01-04.
Rafael Resendez Ramirez was born on August 1, 1959, in Izcar de Matamoros, Puebla, Mexico.
Carlos de los Cobos was born on December 10, 1958, in Matamoros, Tamaulipas, Mexico.
Mariano Diaz was born on 1939-09-17.
Miguel Matamoros was born on May 8, 1894, in Santiago de Cuba, Cuba.