The 22-year-old right-back, who has been capped at senior level by England, opted to join the Hammers after beating off competition from several of their Premier League rivals to secure his services.
Jenkinson said he had no hesitation about moving to the Boleyn Ground as soon as he heard West Ham were interested in bringing him to east London, thanking joint-chairmen David Sullivan and David Gold and manager Sam Allardyce for the opportunity.
“It’s brilliant how it has turned out and I just want to thank the gaffer and Mr Sullivan and Mr Gold because they put in a big push to get me here,” said Jenkinson.
“I’m clearly seen as a big part of things here and hopefully I can prove my worth here because it is an important year for me.
“I was flattered to have a lot of options but, deep down, if I was being honest with myself West Ham was always the place I wanted to go to. It’s one of them where I wanted to do the right professional thing and consider all the options, but in the back of my mind it was always West Ham and I’m just so glad it’s all worked out how I wanted it to in the end.
“It will be brilliant to play here. I’ve got a lot of friends who are West Ham fans and I know how good the supporters are here. I’ve played here a couple of times so I know exactly what it is all about, so it’s going to be fantastic to be a part of that, to be honest.
“You get a great atmosphere here and the fans are great, so I just can’t wait to get a West Ham shirt on and get on the pitch and play. This is an exciting time for me, it really is.”
Jenkinson becomes West Ham’s sixth summer signing, following the arrival of Argentine forward Mauro Zarate, Ecuador FIFA World Cup striker Enner Valencia, Senegal defensive midfielder Cheikhou Kouyate, left-back Aaron Cresswell and another Charlton youth-team product, midfielder Diego Poyet.
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