Get good legal advice about visas and immigration before planning a move to the US
Many people falsely assume that they will be allowed to stay here if they own property here or they are retired. Unfortunately, no amount of property ownership, nor being retired, gives you the legal right to stay in the USA. Unfortunately, many TV programs and magazines in the UK are telling people all about those lucky people who move over to Florida and lead a wonderful life in the sun, making it look very easy. This is just not true! There is very definitely a lot more to it than the UK media portrays. Even having family in the US will not get you in here, because although a US citizen is allowed to sponsor immediate family, in reality, there is a backlog of some 12 or 15 years, during which time you must wait in your own country.
If you have $500,000 available, you may be interested in the EB-5 visa, which is probably the easiest and best way for you to obtain permanent residence in the US. If you don't have $500,000, then the easiest way is to buy an ongoing business, but there are strict requirements for that. While the guidelines are not actually set in stone, a rough guide of a minimum investment for a business is now close to $200,000, with most of that coming from the buyer's personal (documented) funds.
Here are some websites
containing useful information on visas and immigration:
IMMIGRATION ONE (Specialist immigration lawyers with offices in US, UK, Canada, Australia and New Zealand)