Record Usage and Interpretation

A man dies 1780s in Virginia leaving a will in which the only specified property (land) went to five sons. No wife or daughters were mentioned, even though he had both. Within months of his death, the widow goes into court to "renounce her husband's will" and "claim her dower rights."  Question: how could she do this?  Is it the same thing as contesting  a will?  Could dower rights trump a legit will?

As an addenda to a question about citations (see "Descriptors in a citation and a question about Church Censuses"), Ann Gilchrist wrote:

Your QuickLesson 4 touches upon my problem. In the archives of my university, I found old photocopies of pages from several cases that deal with property destruction by the U.S. army during the Civil War. Each photocopy has a pencilled note that reads "French-American Claims Commission no. xxxxxxx, National Archives." I wrote the National Archives but they say I did not give them enough information for them to locate the cases among all their records. Can you help?