Grammar
Online Grammar & Writing Handbooks
K-6
Scott Foresman, PDF files, VERY NICE!
Lectures on Language
As Particularly Connected with English Grammar
by William Stevens Balch
Gutenberg Text
Highschool/College Level
Graded Lessons in English
an Elementary English Grammar Consisting of One Hundred Practical Lessons, Carefully Graded and Adapted to the Class-Room
by Brainerd Kellogg and Alonzo Reed
Gutenberg Text
Also Page Images at Nineteenth Century Schoolbooks
Higher Lessons in English
by Brainerd Kellogg and Alonzo Reed
Gutenberg Text
Practical Exercises in English
by Huber Gray Buehler
Gutenberg Text
Outlines Of English Grammar
by C.P.Mason, B.A., F.C.P.
DjVu Internet Archive
An English Grammar
by W. M. Baskervill and J. W. Sewell
Gutenberg Text
This seems best for older children to me, perhaps early-teens
A Grammar of the English Tongue (1812)
by Samuel Johnson
Gutenberg Text
English Grammar in Familiar Lectures (1829)
by Samuel Kirkham
Gutenberg Text
Stories That Words Tell Us
by Elizabeth O’Neill
Gutenberg Text
Spelling
McGuffey’s Eclectic Spelling Book
by William Holmes McGuffey
Gutenberg Text
The American Spelling Book
by Noah Webster
Text & Page Images at MerryCoz
My Own Primer, or, First Lessons in Spelling and Reading
by Rev. John P. Carter, 1862
MSU Sunday School Books in 19th Cen. America
1001 Questions and Answers on Orthography and Reading
by B. A. Hathaway
Gutenberg Text
Slips of Speech:
a Helpful Book for Everyone Who Aspires to Correct the Everyday Errors of Speaking
by John Hendricks Bechtel
Gutenberg Text