Does anyone know whether we need to obtain the certificates of citizenship for our two sons (born in US to US citizen mother and Canadian citizen father) prior to immigrating or can we just obtain these after we cross the border?
You can do the citizenship after you cross the border. In my case, we applied for Canadian citizenship asap after my kids got all their required docs for citizenship, (social security, US birth certificate, US passport and US passcard). Wanted to have 2 photo IDs needed. US passport and passcard fulfill this requirement. However I was told that US passport, social security and birth certificate was all I needed for docs for proof of Identity.
That said, the kids gotten their citizenship before we crossed the border and before we submitted inland PR application. The fact that the kids had citizenship docs, made the PR application much more simpler.