If you run Texmaker for Windows and need US English (or other) spelling, here is how to fix that.
1. Get the dictionary file en_US.oxt from Open Office [link] [Google search]
2. Rename the file to en_US.zip.
3. Unzip it.
4. Copy both en_US.aff and en_US.dic to your default or preferred dictionary location.
5. Use Texmaker >Options > Configure Texmaker > Editor > Spelling dictionary to select en_US.dic as your preferred spelling dictionary.
Here is Janet and John talking about this:
