“From A to B and Back Again” — the Whitney Museum’s latest exhibit — offers a window into the life and work of Andy Warhol, the iconic American artist best known for his starring role in the Pop Art movement. The retrospective spans from the 1950s, when he worked as a commercial illustrator, up until his untimely death in 1987. In the interim, we are introduced to a new side of the artist — a “Warhol for the 21st Century.” On view through March 2019.