The first power vacuums were invented in 1898 and had a combustible engine. It was built for commercial use so a company would show up at someone's home and run a hose from their horse-drawn carriage (where the combustible engine was), and then the representative would vacuum the house.
The first home vacuum cleaners came along around 1905 and included one called "The Domestic Servant" and another called "The Domestic Cyclone" but they still required some manual labor to create the suction.
Then thanks to both Edison and Westinghouse, electricity became available and a department store janitor invented an electric sweeper in 1908 that became a big hit. In case you're wondering, he was able to quite his janitorial job. Could you imagine if these inventors saw a Roomba vacuum?
Considering it's been over a hundred years the vacuum hasn't changed too much with the exception of suction power, weight, and attachments. On a personal note and from a vacuum cleaner's perspective, the worst thing that ever happened to them was the invention of shag carpet.