Attached are the results of converting these, first to HTML using
AbiWord, and then to ePub with calibre.
Calibre can convert OpenOffice's ODT format directly to ePub, and you can do this through a GUI, but it was easier for me to convert to HTML first, since I could then see what tags should be used for chapter detection for the table of contents. Unfortunately, I couldn't include both the names and the numbers of the chapters in the ToC, because you have these set up on different lines with different styles, and so they're not treated as a unit.
Anyway, I prefer to convert via the commandline with calibre. I used this command and options:
ebook-convert "Alexis de Tocqueville - Democracy in America, Vol. 1 a.html" "Alexis de Tocqueville - Democracy in America, Vol. 1 a.epub" --output-profile="sony" --remove-paragraph-spacing --chapter="//h:h3" --page-breaks-before="/" --authors="Alexis de Tocqueville" --title="Democracy in America: Vol. I"
This tells is to optomize for Sony (which as far as I know only prevents the chunks inside the ePub from being too big for a Sony reader to handle); it prevents calibre from putting spaces between paragraphs, it detects chapters at H3 headings (which is what the chapter numbers became after conversion to HTML), it prevents page breaks elsewhere (which otherwise would put a page break in between the chapter number and title, since both are different heading levels), and sets the metadata for author and name.
This could be improved with a cover page image (--these use calibre's default--), including the chapter number and name inside the same tags, and a few other ways, but they're a good start.
I'm a strong opponent of using WYSIWYG editors like OpenOffice or Word for making ebooks. It's important to see the mark-up, to make things like automatic ToC detection very easy. Hence, I prefer to directly write HTML or LaTeX, and then convert to other formats as need be. But I realize I'm in the minority on that, and if you're willing to put up with the challenges of a WYSIWYG editor, and are careful to use styles consistently, more power to you.
You might try the OpenOffice ePub export plugins -- there are two under development with development versions for download in the ePub forum.
I've barely looked at the results, so all manner of oddities may remain.
I definitely dislike spacing between paragraphs, and prefer indented paragraphs instead, except in business letters or informal writing.