I moved it outside and kept watering it. It was slowly losing leaves. In May I put it in the ground and fertilized it. Currently it is thriving and growing green leaves.
Poinsettias (Euphorbia pulcherrima) originate in Mexico and were introduced to the US in 1828.
I am supposed to put it in the dark for at least 12 hours a day for several months in the fall for the leaves to mature red.
We shall see about that.