The former Kansas City Wizards striker told fulhamfc.com: "Being a consistent goal scorer year after year was something I felt I had to prove in order to make that move.
"My last year in the MLS I looked myself in the mirror and asked myself where I wanted to be in years to come and what was it going to take for me to be more successful at international level.
"I knew it was time for me to make a change. I was the MLS for seven years and I knew that if I wanted to get where I wanted to be I had to go to Europe and get used to playing in front of the big crowds, playing against the best players in the world and was ready to make that challenge.
"I was with the US national team in LA in January and that's when I found out through my agent that Fulham were interested. I knew where they were in the table but it didn't stop me wanting to come over and pursue my football here.
"It is definitely a new experience. But we follow the Premier League in America and I just thought Fulham was a great team. When Clint and those guys were playing I was watching every game and I found myself thinking how can they be where they are. There is nothing I've gone through in life that I haven't been able to overcome so that's why I was not afraid of the challenge in coming over here."