how do you think american childhood has and hasnt changed since the 1840s?

Well, it has changed a lot from a practical perspective.

Grades in school matched with a child's age and ability.

Different programs for different children.

Better healthcare.

Officially non segregated population.

No slavery (legally anyway)

Some things have not changed.

abusive parents.

alcoholic parents.

child's sense of exploration

society imposing values on children

Sorry this isn't in paragraph form but this should get you started!