<i>I don&#x27;t think that&#x27;s the case: an unpatented invention (that is disclosed) becomes prior art, which protects the invention from being patented by someone else.</i><p>If an unpatented invention is disclosed publically (not through a patent application), then it becomes public domain and nobody can patent it.<p>Also, the US is no longer &quot;first to invent&quot;, but rather &quot;first to file&quot;.  You could have a claim that you invented it first, but if someone files before you, you are SOL.