"It feels good to be back. This (Fulham) has always seemed like my home in Europe and I am excited to be back and be part of this team and play in this league," he told the club's official website.
"I wanted to get back to playing at the highest level and getting back and helping the team in the situation where they are not where they want to be in the table.
"But going into a World Cup year you want to get into that top form and carry that forward so hopefully I can have a good showing."
Dempsey, who will use the MLS offseason to get back to playing in the Premier League, spent five-and-a-half-years with the Cottagers between 2007 and 2012, scoring 60 goals in 225 appearances.
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