The process is long and arduous....and costs a bit of money. If you have never been to an INS office it SUCKS. The few times I have been to one the people were rude and inconsiderate and treated the customers like crap. I think you have to have a fairly clean record also. I am sure they limit the AMOUNT of people that become citizens each year also...maybe they do a lottery or something. Between the wait, the cost and having to not have a record...well...a lot of hispanics just sneak across. There are a lot that do it the right way also and they are to be applauded because the system sucks for those who want to do it the right way.....
*NOTE...the citizensship test....well...there are people here in the U.S. that couldn't answer some of those questions that were born and raised here.
I'm sure someone on here will outline the process step by step but it is by no means easy...nor should it be...because being a U.S. Citizen is something special!!!