How did New York city get the name "The Big Apple"?

The big apples is actually an old saying - when people starting migrating over here they all endedup in NYC _ NYC as you know is huge and has alot to offer so many different people - "reach for the BIG APPLE" you know what i mean, people would tell others to accomplish there goals and dreams this way. Reach for the best and highest achievement you can get which is where the city eventually adopted its name for all of its opportunities, eventually architectures and design picked up on the note as well by making the worls largest tallest buildings. Make them tall and powerful looking. it represents againt - the apples on the tallest tree - you reach for that apples - its up so high
how is that for an explanation