How much of congress must approve an amendment to the us constitution before it is sent to the state?

Of all the gas giants, neptune has the longest period of revolution. : )

If you mean how the great lakes formed, then  the great lakes began to form at the end of the last glacial period 14,000 years  ago, ice sheets  retreated, which led to exposing the basins they had carved into land which then filled with melt-water.