Can I petition for him as well even when if I did petition my first husband 16 years ago?

Generally, a foreign national married to a U.S. citizen may succeed in consular processing to be able to enter the U.S. and to become a Lawful Permanent Resident (to get a "Green Card"), and this is true even if the U.S. citizen spouse previously sponsored a former spouse in a marriage-based case. The USCIS can be expected to apply a heightened level of scrutiny where the U.S. citizen previously applied for a different spouse (including further evaluation of whether the first marriage was bona fide). It would be wise for you and your partner to consult with an immigration attorney who, after learning all of the relevant history about you, your partner, your former marriage and the previous immigration case, could advise about immigration eligibilities, options and strategies, and could offer legal representation in the often quite complex application process.