The Federal Election Commission has published a 256-page book, “Federal Election Campaign Laws.” It can be seen on-line here. Also, anyone may obtain a free print copy by phoning 800-424-9530 and pushing option 6. Or, e-mail the FEC at info@fec.gov to request a copy.
The bulk of the book consists of Title 52 of the U.S. Code, “Elections”; and Title 26 of the Internal Revenue Code. There are other code sections from other codes in the Appendix. Thanks to Thomas Jones for the link.