A spouse's ability to work is often the most important factor when looking at work visa options for a founder. The visa classifications that give spouses (and only married spouses can get dependent visas under U.S. immigration law; common-law spouses can't) unrestricted work authorization are the E-1 and E-2 visas, the E-3 visa, and the L-1 visa. Fortunately, Mexican and Canadian citizens have their own visa classification, the TN, so this is another option for spouses although this would require direct sponsorship by a U.S. employer.