The Dunford-Pettis property for Lipschitz-free spaces over ${\mathbb{R}}^n$

We show that for every $n\in \mathbb{N}$, the Lipschitz-free space $\mathcal{F}({\mathbb{R}}^n)$ has the Dunford-Pettis property. As a consequence, for every $n\in \mathbb{N}$ and every nonempty $M\subset {\mathbb{R}}^n$, the space $\mathcal{F}(M)$ has the Dunford-Pettis property. This implies that $\mathcal{F}(M)$ is not isomorphic to $\mathcal{F}(X)$ for any separable Banach space $X$ that fails the Dunford-Pettis property. In particular, this applies to $X={\mathrm{\ell }}_2$, and more generally to every infinite-dimensional separable reflexive space. We also deduce that if $1<p<\mathrm{\infty }$, then $\mathcal{F}({\mathrm{\ell }}_p)$ is not isomorphic to ${({⨁}_{n=1}^{\mathrm{\infty }}\mathcal{F}({\mathrm{\ell }}_p^n))}_{{\mathrm{\ell }}_1}$.