Ash Ketchum is the protagonist of the Pokemon anime series. His goal is to be the world's greatest Pokemon Master. His hometown is Pallet Town and his very first Pokemon was Pikachu.
Ash has traveled through many regions capturing new Pokemon and battling Gym Leaders to qualify for that region's Pokemon League competition. Ash also seems to have a close connection with various legendary Pokemon such as Ho-Oh; who he has seen multiple times throughout the series.
In the English dub version of the Pokemon anime series by 4Kids Entertainment Ash Ketchum was originally voiced by Veronica Taylor.
Veronica Taylor would voice Ash for 8 seasons of the Pokemon anime and 8 anime films.
In 2006 4Kids Entertainment lost the license for the Pokemon anime to Pokemon USA. Pokemon USA then made the controversial move of recasting all the 4Kids voice actors.
The 10th anniversary special Mastermind of Mirage Pokemon was a testing ground for the new voices. In this special Ash Ketchum was voiced by Kayzie Rogers under the pseudonym of Jaime Peacock.
Fans criticized the voice (among other things) so Pokemon USA then hired Sarah Natochenny to voice Ash Ketchum for the anime series and all future Pokemon films. Pokemon USA would later re-dub the Mastermind of Mirage Pokemon special with Sarah Natochenny as Ash.