Why do you suppose Cal decides against corresponding with Ana?

At the end of the book, Ana tries again to contact Cal but is ignored. Why do you suppose Cal decides against corresponding with Ana?

It was disappointing and I am unsure why the author chose to end their friendship in that way. Perhaps showing that prejudice can take on many forms, even for people who are friends? Hard to say.

It is hard losing a good friendship when you are young or at any age and especially how Ana did it, just disappearing. I would feel the same way that Cal did. Friends need to stick together.

Perhaps the author is wishing to point out that while usually we think of racial prejudice being white against minority, it can be present in the reverse as well. Cal may be assuming that Ana can’t be completely trusted simply because she is white, despite their friendship. A sad loss for both women.

Cal may have stopped corresponding because Ana had abandoned her when she needed most and now Ana tries to reach out but Cal rightfully rejects her.

I don't think that my answer offers any new insight here. I believe that Cal may have felt left out of Ana's life at a time when she, Cal, felt most vulnerable and in need of a best friend. And then, as others have suggested, it is possible that Cal's rejection of Ana is an example of reverse discrimination,

Im not sure why the author had this in the story. Good for a discussion point as noted in above comments

I am agreeing with all who have spoken here. Ana was not present for Cal when she was most greatly needed, and perhaps she adjusted to life without her best friend. As a result, when Ana reached out, Cal was unable to or chose not to respond.

First, I don’t think it was reverse prejudice. Ana and Cal had a rough patch or two early in their friendship. Ana’s mother did not encourage the friendship, as I recall. Cal had to protect her own Underground Railroad activities and those of others. That was nothing to be toyed with. Perhaps by the end of the book, the two women had been apart for too long to renew their friendship. Unlike today, they couldn’t keep in contact via Zoom, email, or text. We can’t really even be sure Ana’s letters reached Cal—nor do we really know whether Cal wrote back.

This is the one area I'd love to ask the author about. I think it's unclear why the friendship faltered, and I'm not really sure why Cal didn't accept Ana's overtures later in life. Perhaps it's as marianned says above - too much time had passed, and it wasn't very easy to contact others.

I thought that Cal had decided she didn't want to pursue the friendship anymore. People grow and change--sometimes they outgrow earlier friendships. I don't see it as necessarily being reverse discrimination on Cal's part.

I thought that Ana and Cal had reconciled when they were both working for the Lincolns. I don’t think their relationship was fully healed but it made the estrangement after Cal left Springfield that much more confusing to me. I wish the author had fleshed out that relationship a bit more.