A copy of the I-94 for your last entry and extension or entry stamp in your passport will be sufficient to demonstrate a lawful entry.
should be, a copy would also work, and didn't they stamp your passport. that works as well
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As proof of you having been lawfully admitted into the US for AOS purposes, in your situation, you could use:
1. Your I-94 number: look for it in the I-539 you filed;
2. The lawful admission stamp on your passport, next to your visa stamp (usually on the very next page of the passport).
Of course you could file a Form I-102 and get a copy of your I-94 card, but why bother and spend the time and money?
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