I think you have the order of events wrong. The connections (and other value) YC provides help you get that funding which lets you hire yourself into the US.

I think you have the order of events wrong. The connections (and other value) YC provides help you get that funding which lets you hire yourself into the US. As pbiggar points out above, there's no problem (at least for EU citizens) getting into the US for three months of YC - it's staying there long term that's hard.