We finally emigrate on 3rd October. We enter the USA at San Diego. Think our flight arrives around 6 pm. Does anyone know how long the immigration process takes at the airport? Getting excited now!! :-)

How longs a piece of string? Depends on how busy secondary inspection is, how well its staffed etc. I'd budget at least an hour and a half- just in case.

Oh that's not sounding too bad then :-)

I don't know about the secondary inspection but San Diego is a small airport with little distance between the international gates and immigration in which to overtake slow people, so if you are near the back of the plane and your flight is full I'd guess you could be in the first line for 45 mins. There are approx. 5 lines for non-citizens, usually well staffed.

BA flight arriving at 6.15pm looks like the only international flight around that time so you shouldn't get held up too much by a flight ahead of you like happens at many other international arrival hubs like Chigago, Miami, JFK, LA

If everything is in order, as I am sure it is due to you diligence, you should sail through in minutes. If they play hardball, a couple of hours. If something is out of order, who knows.