Passage: By 1999, Iglesias had begun a successful crossover career into the English language music market. Thanks to other successful crossover acts, most notably that of Ricky Martin and Gloria Estefan, Latino artists and music had a great surge in popularity in mainstream music. After attending one of his concerts in March 1999, Will Smith asked Iglesias to contribute to the soundtrack of his movie Wild Wild West. His contribution "Bailamos" was released as a single and became a number one hit in the US.

Question: Into what area had Iglesias successfully crossed over by 1999?
the English language music market