Eminent domain is the power of government to take private property and use it for public use.

Every state has laws regulating how government can take the property of private landowners. In many states, the government is required to negotiate with the property owner before actually taking the property. In some states, the government can begin legal proceedings to take property without giving prior notice to the property owner.

An eminent domain lawyer is a necessity in adequately protecting your interests in public hearings and governmental procedures. There are technical hoops and deadlines which must be met to contest the taking of your property.

While you can't stop the government from taking your property, an organized group of neighbors can sometimes convince government officials to reroute or redesign a government project to place less of a burden on the neighborhood in general and specific landowners in particular.

The Property Condemnation Process
When the government condemns your property and takes it for public use:

You'll first get a letter from the government showing an interest in your property and naming the government project involved
The government will then appraise your property to determine its fair market value. Under the federal constitution, you must be "justly compensated" for your property.
You'll receive a "pro tanto award" from the government offering a specific amount for the property they want to take
If you accept the offer, the government will ask you to sign legal releases waiving your right to sue the government
If you don't accept the government's offer, the government will take the matter to court in an eminent domain proceeding.
If you decide to go to trial on the issue of how much your property is worth, you'll need an experienced eminent domain lawyer to represent you.

Courts have interpreted what projects are for "public use" - and appropriate for the government to take property to construct- very broadly over the past few decades, so it won't do any good to argue that the particular project isn't really for the "public use."

At trial, a jury will listen to various experts testify as to how much your property is worth, then set a specific amount the government must pay you for taking your property.

In addition, the government must pay your moving and relocation expenses.