The Yellow Rose Of Texas
Texas Facts
More Texas Facts
A major resource for Texas history, this has links to original documents and great little know information. Done by people who eat sleep and breathe Texas History. ~Jube

All 50 states with lots of information

Texas Official Website
One of the First Sites for Texas Teachers, the Armadillo has not been updated, but still has great information.

http://eleaston.com/materials.html#CountryProfiles
There are four Texas sites, under Country Profiles--US: ~Eva

The Internet Public Library KidsSpace has this on Texas.

Here's one someone sent out that has TONS of info on Texas; it's called the "Handbook of Texas Online" and is a "multidisciplinary encyclopedia of Texas." ~Shirley (This is often referred to on the teacher lists I'm on~ Jube)

The Spanish Explorers materials ~Don  This has original papers, great references to books for your children to enjoy.  It's not in a normal format, so it will take a bit of digging, and you need 2 windows open, one to this site, and one to Amazon ;-) ~Jube
Educational Resources from The Alamo, be sure to get their newsletter.  *I got wonderful materials while at the Alamo and then later started receiving their newsletter. It contains copies of primary documents, articles about history, news about Alamo events, etc.~Melanie
About.com's Homeschool Guide just did a study for all 50 states.  Here is their Texas Page.~Jube
Vikings in Texas, who knew?
Another cool site called Texas Beyond History has a kids page and a teachers area.
The Texas State Library and Archives has a great site, but it's best left to high schoolers since there are so many original documents on this site.
If you want a quiz, the official Texas Quiz is archived here.
For Information on the Alabama Coushatta Indians of Texas
The Cowboy Museum may be in Oklahoma City, but their site is great for the little ones. From songs, stories, printables and other great stuff, this site will work wondering on one of your slow days.  Lots of animation and games. ~Jube
"Remember Texas" Booklet Highlights Historic Sites is in PDF format that you download and then print.
Great book to stick in your glove box
March 2, 1836 is Texas Independence Day and this site has all the information you could use about it.
The State Library and Archives also has a genealogy section for researching YOUR Texas Roots.  By finding people in your family who were around when historical events took place, you help bring history into your child's personal story.   Great impact.
But if it's a beautiful day outside, consider doing a Fort Tour of the many forts in Texas.
Just found this new site which is from a non profit organization call the Lone Star Junction, with a Texas History Timeline. hope you like it.
The Bob Bullock Museum is really the State of Texas History Museum, so take a field trip to Austin.  Many of their items are online:

Online Texas history at the University of North Texas
 
There is the Texas History site:  which if you click any other page will have actual history and not just the sales stuff.
Happy Texas Trails to You!