My partner and I will be going to Canada on a 2 year Working Holiday Visa and want to travel through the US intermittently as we earn the money. I know I can't go through on a visa waiver because I will be in the continent for more than 90 days, but to be eligible for the B1/B2 visa, you need to prove you have a residence to go back to, etc and we wouldn't have that. Are there any other Aussies, Brits, etc who have done something similar and can help? How do the US know when you leave? Thanks in advance.