Amelia Earhart is a legend in American feminism and the subject of a movie released this year. George Putnam had a hard time winning her hand having proposed six times before they were married on Feb 7, 1931. Earhart had some very liberal views on marriage as characterised by a letter she had hand-delivered to Putnam on that very day. A copy of the letter can be found here:
Within, Earhart attests to being very reluctant to marry. She refuses to hold George to what she termed "medieval codes of faithfulness" and seemed to encourage both of their lives, and love interests, would remain separate, and even eludes to marriage being a "cage". Clearly, Amelia was concerned over the implications concerning marriage and even asked for a provision in the marriage contract: "I must exact a cruel promise and that is you will let me go in a year if we find no happiness together."
Earhart was a prominent figure in an age of adventurers and she was probably very aware of the feminist message that she portrayed as a single woman. After her marriage, she even kept her own name - a fact mercilessly preyed upon by the press. Brave and honest, she didn't make compromises on what she wanted and specifically articulated her hope for mutual freedom, passions, and loves in their arrangement. Earhart wasn't afraid to take risks. The last line of the letter strikes me as the most honest and genuine:
"I will try to do my best in every way and give you that part of me you know and seem to want."
Amelia is, precisely - to me - what poly seems to be about.