This is a question that we have all asked ourselves at some point. Being at home in front of the computer or in front of an encyclopedia or with luck, standing on one of its sections scanning the horizon and marveling at such a man-made structure.
Well, there are no short answers but yes, it was not done overnight or at a particular moment in history. Actually, the Great Wall is a series of walls that many Chinese dynasties built since 656 BC, at which time the Chu state built a wall, the first.
The Chu Wall was fortified by Emperor Qin Shi Huangdi around 221 BC and then what would eventually become the Great Wall began to take shape. Later many dynasties made their contribution by adding new kilometers or subtracting it, but the greatest contribution was during the ming dynasty. Then all the isolated walls were connected, so what we see today are the remnants of this restoration.
It took 97 years