“Mexodus”: compelling, eloquent musical evokes American slaves’ underground railroad to Mexico

"Mexodus," written and performed by Brian Quijada and Nygel D. Robinson, is an historical musical that feels urgent, inventive, and moving. Directed with clarity by David Mendizábal and performed with raw conviction by its two actor-musicians, this off-Broadway production reclaims a forgotten chapter of American history — the thousands of enslaved people who escaped not north, but south to Mexico,…