Early Sewing machines were either hand powered or foot powered as shown in the photo above, as electricity was not yet invented.  These type of machines were considered a major improvement over hand sewing.  But still getting things done and production was limited to the amount of energy the sewing machine operator could do.  The first machine only used one thread to create a "chain stitch", unlike the machines today which use two, the spool of thread and the top and the bottom thread which is known as the bobbin.  The old machines that only used one thread unraveled quite often which resulted in seams unraveling and falling apart because the stitching didn't "lock".  Many  working "toy" machines today are like that and I do not recommend getting them if your child is interested in sewing. 

In 1854, a man by the name of Elias Howe introduced the first "lock-stitch" sewing machine which used two threads to "lock" together and create a stitch.  This stopped the unraveling problem.

Later the electric motor was added to the sewing machine which allowed the seamstress to sew much faster and produce more garments or products.

Later in years other inventors like Isaac Singer and A.B. Wilson improved on the "lock-stitch" sewing machine idea and created machines used today.