It depends what is your present status. If you are neither a UK citizen nor a US citizen already, then I canu2019t offer much advice, other than that itu2019d be a complex and long journey, if even possible.If you are already a UK citizen by birth, to become a US citizen youu2019d first have to acquire a visa in order to stay for a set amount of time in the USA - a work visa, sponsored by an employer, or a student visa, or a marriage/fiance visa if you are or are intended to be married to a US citizen. Itu2019s not an easy route, nor a quick one. I did it, and in my case it entailed my now husband, a US citizen, staying with me in England for around a year. He had to acquire a visa to do so, and an extension of it after a given period, while I applied for a marriage visa. Thereu2019s money involved at every stage - itu2019s not cheap!Once we were married, in England, I applied for a visa to come to the USA with my husband. This took a while, and involved a trip to London for medical examination and an appointment at the US Embassy.Once settled in the USA , after selling my UK property, and sending what I could of my belongings by sea, my visa covered me for a limited amount of time, after which I had to apply for an extension. This extension would, I think, have covered a further 10 years stay. In the meantime, 4 years after arriving here, I applied for US citizenship - this was not obligatory, I chose to do so. It took a while due to backlogs in the system, but eventually I took the citizenship test and went through all the required red tape, attended a ceremony - about which Iu2019ve written already at Quora.I held both passports for 10 years, but havenu2019t renewed my UK passport as I have no intention of travelling out of the country - but I remain a dual citizen.If you originally obtained a visa via employment or student routes, then I am not certain how the journey would proceed. Provided that the employment continued, youu2019d probably have to renew the visa, until such time as you could apply for citizenship. If the student route - I think that visa would not cover you for long enough unless you obtained employment here and changed your visa type. Thereu2019s a British Ex-pats forum where they freely offer advice on all routes and all visa types - just Google search u201cBritish Ex-Pats Forumu201d, go to the USA section.If you are already a US citizen and wish to become a UK citizen, the above route would work in the other direction, but I do believe itu2019s slightly less daunting that way, from the experience we had when my husband stayed in the UK. I am not certain that the US government would consider you still a US citizen, though, were you to become a UK citizen.