The details that support the central idea of the passage are:
- “the immeasurable contrasts between the two lives which it connects”
- “I did not know what the future held”
- “It was the third of March, 1887”
- “I went to the door and waited on the steps”
These details highlight the significance of the day Anne Sullivan arrived and the transformative impact it had on Helen Keller's life, emphasizing her anticipation and lack of knowledge about the future. The mention of the specific date also anchors the event in time, adding to its importance.