Throughout history, the works of inventors, engineers, and entrepreneurs have advanced mankind in both small steps and giant leaps forward. But not all of those designs came to life while the hearts of their creators were still beating.
Sometimes it was an abrupt death. Other times, it was lack of funding or public interest. Some inventions were even vague or hastily scrawled designs in the originator's notebook. But many of them were finally built, sometimes hundreds of years after that person died.