#69 Carnegie's Maid by Marie Benedict

Quote
In the industrial 1860s at the dawn of the Carnegie empire, Irish immigrant Clara Kelly finds herself in desperate circumstances. Looking for a way out, she seeks employment as a lady's maid in the home of the prominent businessman Andrew Carnegie. Soon, the bond between Clara and her employer deepens into love. But when Clara goes missing, Carnegie's search for her unearths secrets and revelations that lay the foundation for his lasting legacy.

I was a little confused as to what was real in this story. However, the author's note at the end clearly states Clara was a fictional character designed to possibly explain Carnegie's change of focus.