There are love stories about kindred spirits. There are others about far-off admirers.

This is a story of both.

In 2014, Christopher Ward visited an art exhibit that explored the relationship between the French Impressionist Edgar Degas and the American artist Mary Cassatt. The two were inseparable in the late 1870s. They kept studios blocks from each other in Paris and met frequently when in town.

Mr. Ward, a playwright, was captivated by the pair. “I looked at my wife and said, ‘This is a play,’” he recently recalled.

Mr. Ward’s “The Independents,” which began performances on Thursday at the Jerry Orbach Theater in Manhattan , explores the artists’ relationship in the late 1870s. “I’ve always loved Mary Cassatt,” Mr. Ward said. Like writers before him, Mr. Ward was curious about the dynamic between Cassatt and Degas. Cassatt, a single woman who moved to Paris in 1866 to pursue painting, left few accounts behind. Degas didn’t write much either. Historians agree, though, that it was one of the most significant artistic relationships of that era.