Inheritance, as a concept, is something that belongs to one person. When you receive inheritance, it belongs to you and only you. Or at least that's the way it seems. When it comes to marriage and comingling your financial resources in joint accounts, it is very easy for your inheritance to become your spouse's inheritance too.
In practice, your inheritance is considered "separate property," which means that your spouse doesn't have a right to it. In both equitable distribution states and community property states, inheritance is treated as separate property -- unless you share or comingle it with other funds that make it a part of the shared property of both spouses.
In these select cases, the inheritance becomes "marital property," and the individual who received the inheritance would have a very difficult time proving that those assets belong to them and them alone. But there is an appeal that someone in this position could make.
If you didn't mean for the funds to be comingled, or if you had no intention for the inheritance to be shared, you could make that argument. It is not guaranteed to work in every case, but it is an option that a divorcing spouse has when property division is being discussed.
Inheritance and divorce is a tricky subject, as is the topic of property division. If you and your spouse are headed for divorce, it behooves you to have an experienced attorney on your side who will fight for your rights and interests.
Source: FindLaw, "Inheritance and Divorce," Accessed Dec. 8, 2016