How it all started......
The History of Children’s Literature Timeline
The History of Children’s Literature
Before the eighteenth century there were no separate categories of books for children. Early books for children were strongly influenced by the conservative English beliefs of the seventeenth century.
In the late 1600's, in a land far, far away England, the relived a British philosopher named John Locke.
He's mostly remembered for his works of political theory.
But for our purposes, let's focus on a short book he wrote in 1693, called Some Thoughts Concerning Education.
Locke wanted to change education and one of his big ideas was to make reading fun. The alphabet, he wrote, should be taught with dice games, and readers should start with "easy, pleasant" books, even books with pictures.
These are not unusual ideas today, but they were relatively new in their time. The first widely printed picture book for kids the Orbis Pictus had been published only a few decades before, in 1658.
As Locke put it, " ... 'tis usually long before Learners find any Use or Pleasure in reading which may tempt them to it."
The popular school books in Locke's time, like the American New England Primer, were not about storytelling. The Primer did have some pictures, but it was mostly tables of letters and syllables, used to help people learn to read the Bible.
As Locke's theories took hold, both in England and in the United States, they shaped many of the children's books that were published in the 1700s

1400's
Horn books were created for children. They had alphabet and bible verses pasted on them. They were popular amongst Puritans.

1500's
Aesop's Fabels Chap books were created. These books were for pleasure verses instruction.

1696
Tales of Mother Goose retold by Charles Perrault.

1700's
A Pretty Little Pocket Book was published by John Newbery. Chap books were little books, sold on the street by peddlers.

1814
The Swiss Family Robinson book was published. Children's book became more creative and started to have more influence.

1864
LittleWomen by Louisa May Alcott.A trend-setting novel that broketradition. The characters and eventsreflected honest human experiences.

1895
The Jungle Books by Rudyard Kipling. Life lessons in an interesting tale set in India.

1900
The Wonderful Wizard of OZ written by Baum. The first classic modern fantasy written by an American.

1937
And to Think That I Saw It on Mulberry Street, by Dr. Seuss

1952
Charlotte's Web, classic Newbery Honor book about animal fantasy. Written by E.B. White.

2000
Newbery Medal Winner Bud, Not Buddy by, Christopher Paul Curtis

2000-Present Time
Children's books have greater diversity.
Conclusion:
The beginning of illustration
Chapbooks, pocket-sized books often folded slightly than stitched together, were the first books to be illustrated for children. They usually contained simple woodcut pictures to go along with their contents often popular ballads, folk tales, or religious passages.
Meanwhile, during the 1600's, the concept of childhood was evolving.Rather than being seen as miniature adults, children were seen as separateentities with their own needs and limitations. Thus, publishers throughoutEurope began printing books specifically intended for children. The purposes ofthese texts were still frequently didactic, although several collections offairy tales were published with varying success.
Modern Children's Picture Books
It was in the 1920's that books could be mass produced incolor and literacy became adequately extensive to make make children'sbooks a true industry unto its own. Wanda Gag's Millions of Cats (1928)was one of the most successful of this era, selling more than a million copies
At this point, there existed several different genres of children’s literature: games, fables, alphabet books, nursery rhymes, poetry,and fairy tales. Throughout the nineteenth century, children’s literature became ever more less didactic in nature and more geared towards children’s imagination and understanding with the reader.
References:
Information retrieved from:
https://www.livestrong.com/article/1004884-john-lockes-ideas-child-development/
https://blog.bookstellyouwhy.com/bid/230055/A-Brief-History-of-Children-s-Literature