Let Y → ℙn be a flat family of reduced Gorenstein curves, such that the compactified relative Jacobian
is a Lagrangian fibration. We prove that X is a Beauville–Mukai integrable system if n = 3, 4, or 5, and the curves are irreducible and non-hyperelliptic. We also prove that X is a Beauville–Mukai system if n = 3, d is odd, and the curves are canonically positive 2-connected hyperelliptic curves.