How did e rise in history?

e is a mathematical constant. But how did e rise?

Morden bankers use complex interest on credit. Suppose the yearly interest rate is r, after one year, the lenders must pay (1+r) dollars for each dollar. However, the banker can use a monthly interest of r/12, and x years equal to 12x months. So the payment is now (1+r/12)^12. Moreover, the banker can use shorter interval for interest time unit.

The universal expression is now (1+r/n)^n -> e^r when n grows to infinity. That's how e rised.