Code
public class Person
{
   public string FirstName { get; set; }
   public string LastName { get; set; }
   public DateTime DateOfBirth { get; set; }
}

List<Person> people = new List<Person>();

people.Add(new Person { FirstName = "Moses",
   LastName = "McRoses",
   DateOfBirth = new DateTime(1801, 1, 23) });

people.Add(new Person { FirstName = "Timothy",
   LastName = "Khouri",
   DateOfBirth = new DateTime(1985, 6, 20) });

people.Add(new Person { FirstName = "Jonathan",
   LastName = "Carter",
   DateOfBirth = new DateTime(1984, 6, 12) });

var param = Expression.Parameter(typeof(Person), "person");

var mySortExpression = Expression.Lambda<Func<Person, object>>(Expression.Property(param, "DateOfBirth"), param);

Person[] sortedPeople = people.OrderBy(mySortExpression).ToArray();