Had issues with eTA for entering Canada via air, but travel had already been booked with my family. When I couldn't travel with them made the decision that I needed to get there via the US on my own. I purchased a return ticket to New York and travelled on to Burlington, Vermont and then drove to Canada. I purchased a return ticket to US as it was cheaper than one way. Fortunately I managed to return home from Canada on original planned flight.
Do I now need to notify the US Immigration or similar that I've returned home to the UK or is this already done via my passport?