Edit and Proofread History Textbook

I'm looking for a thorough proofreader and editor for an elementary-level history textbook. The book requires:

- Basic grammar and spelling corrections.
- Refinements in style and tone for age-appropriateness.
- Fact-checking and ensuring content accuracy.

Ideal skills and experience:

- Strong command of the English language.
- Experience with educational content, especially for elementary students.
- Background in history is a plus.
- Detail-oriented and reliable.

Please provide samples of previous work.