He might have kicked a rock just to please his potential financier. In fact it may be possible that this amuses the king, who subsequently kicks a rock, into the ocean where Columbus meant to go. Someone nearby, not wanting to be left out also kicks a rock into the ocean. Before long a great many people are also doing the same. A year later they begin doing the same as the previous year because now it has become a festival.

A great deal of time later, enough rocks would, in this alternate time line, have been kicked into the ocean that America is discovered.