Many recent legislative history materials are available online.
A legislative history is a collection of materials that helps explain the meaning of a bill. This means that the first step is identifying relevant session laws.
Oregon Revised Statutes: Historical Notes
If you are working with a section of the Oregon Revised Statutes you can use the history note to identify the various enacted bills or session laws that have modified that section.
Each entry in the note is separated by a semicolon. The entries all cite to a chapter of the official publication of Oregon's session laws Oregon Laws.
If the first note is preceded by “Amended by” the section pre-dates the ORS and a more advanced examination of prior statutes is required. Repealed and moved ORS sections will retain their historical notes where the sections were previously located.