Genetic selection and engineering before CRISPR

Quite often genetic manipulation is understood as a synonym of CRISRP/Cas9, but this has not always been the case.
Genetic manipulation can be defined as any human intervention that impacts traits of plants, animals or microorganisms which will be inherited in the next generation.
Our ancestors, thousands of years ago, started the genetic manipulation of corn, crossing plants that had more kernels in the corn cob. Also, selecting and cultivating specifically bananas, carrots and potatoes that were bigger, juicier or with less seeds. Another level of genetic manipulation is mixing plants to create hybrids, like the blood lime.
Finally, another example among many others are the chickens that we eat currently; they have been selected to have huge breast that do not resemble at all a wild chicken.
In all the previous cases human direct intervention has impacted the genome, the DNA of these organism without any modern genetic technique.
The difference with the gene editing tools like CRISRP/Cas9 is that our current know-how allows us to modify plants and animals with less trial-error and faster.