Maxwell's equations are four equations known to Maxwell; but it seems to me that they are GFAM's (Gauss-Faraday-Ampere-Maxwell's) Equations.
Why are they then called only Maxwell's Equations!?
This additional term to Ampere's Law is discussed in the Wikipedia article on Maxwell's Equations.
So yes, the consolidation of the four separate laws discovered by Gauss, Faraday and Ampere very much is a contribution unique to Maxwell, though individual laws still carry the names of their original discoverers, and are taught in that way in elementary physics curricula.