Elizabeth Barrett Browning.
Dominated by her possessive father, Elizabeth spent most of her time alone in an upstairs room. In the first two lines he say's that "Shall I compare thee to a summers day?
An accident while saddling her horse left her with an intense head and spinal pain with loss of mobility. It is a way of saying that love within her is limitless, and that mere numbers cannot be held accountable for. She loves him as naturally as her breathing. It has a female narrator which was highly unusual for the time.
You can imagine her pent up strength of feeling and sense of relief.
Industrialization was transforming the citizens into a working class population and as a result, it was creating new urban societies centered on the factories.
However, you will not find any numbers in the poem. In other words, her love consumes every inch of her being; not just mortal coils, but even her soul.