How does inheritance law protect a surviving spouse from being completely disinherited in the United States?

In the United States, inheritance law protects a surviving spouse from complete disinheritance through several legal mechanisms that vary by jurisdiction. Every state employs one or more of the following devices to ensure the surviving spouse receives a portion of the decedent's estate:1

• Indefeasible Share: This is the most widespread protection, guaranteeing the surviving spouse a specific portion of the estate, typically defined as a fixed dollar amount plus a fraction, or simply a fraction of the total estate.1
• Community Property: In jurisdictions that follow this system, the surviving spouse is entitled to one-half of the community property, which generally includes assets acquired through the gainful activities of either spouse during the marriage.21
• Dower and Curtesy: These modernized common-law estates may grant the surviving spouse a life estate in all or part of the deceased spouse's real property. However, these are less common today as they often apply only to real estate rather than personal property.1
• Homestead and Family Allowances: These laws provide immediate financial security by awarding the surviving spouse income or property from the estate for a period following the death.1