Как назначить многоуровневое свойство в списке C#?

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public class country {
    public int id {get;set;}
    public string name {get;set;}
    public int Lats {get;set;}
    public int Longs {get;set;}
    public List<states> states {get;set;}
}

public class states {
    public int id {get;set;}
    public string name {get;set;}
    public int Lats {get;set;}
    public int Longs {get;set;}
    public id countryid {get;set;}
    public List<citys> citys {get;set;}
}


public class citys {
    public int id {get;set;}
    public string name {get;set;}
    public id countryid {get;set;}
    public id stateid {get;set;}
}


//-------------

//Data Access

public DataTable getCountry(){
    DataTable dt = new DataTable();
    _conn = new Connetion();
    using(_cmd = new SqlCommand()){
        ------param------------
        using(SqlDataAdepter da = new SqlDataAdepter(_cmd)){
            da.Fill(dt)
        }
    }
    return dt;
}


public DataTable getStates(){
    DataTable dt = new DataTable();
    _conn = new Connetion();
    using(_cmd = new SqlCommand()){
        ------param------------
        using(SqlDataAdepter da = new SqlDataAdepter(_cmd)){
            da.Fill(dt)
        }
    }
    return dt;
}


public DataTable getCity(){
    DataTable dt = new DataTable();
    _conn = new Connetion();
    using(_cmd = new SqlCommand()){
        ------param------------
        using(SqlDataAdepter da = new SqlDataAdepter(_cmd)){
            da.Fill(dt)
        }
    }
    return dt;
}

//-------------

//Method

public void AllLists() {
    DataTable dt = new DataTable();
    country c = new country();
    dt = getCountry();
    country = (from DataRow dr in dt.Rows
        select new country(){
            countryid = dr["id"],
            states = ------how to add a states----,
            states.citys = ------------how to add citys-----
        });
}

ниже приведен формат, как я хочу получить данные
в формате json

country: {
    id : "",
    name : "",
    Lats : "",
    Longs : "",
    states : {
        id : "",
        name : "",
        Lats : "",
        Longs : "",
        citys : {
            id : "",
            name ; "",
            countryid : "",
            stateid : ""
        }
    },
country: {
    id : "",
    name : "",
    Lats : "",
    Longs : "",
    states : {
        id : "",
        name : "",
        Lats : "",
        Longs : "",
        citys : {
            id : "",
            name ; "",
            countryid : "",
            stateid : ""
        }
    }
}

}

Что я уже пробовал:

public class country {
    public int id {get;set;}
    public string name {get;set;}
    public int Lats {get;set;}
    public int Longs {get;set;}
    public List<states> states {get;set;}
}

public class states {
    public int id {get;set;}
    public string name {get;set;}
    public int Lats {get;set;}
    public int Longs {get;set;}
    public id countryid {get;set;}
    public List<citys> citys {get;set;}
}


public class citys {
    public int id {get;set;}
    public string name {get;set;}
    public id countryid {get;set;}
    public id stateid {get;set;}
}


//-------------

//Data Access

public DataTable getCountry(){
    DataTable dt = new DataTable();
    _conn = new Connetion();
    using(_cmd = new SqlCommand()){
        ------param------------
        using(SqlDataAdepter da = new SqlDataAdepter(_cmd)){
            da.Fill(dt)
        }
    }
    return dt;
}


public DataTable getStates(){
    DataTable dt = new DataTable();
    _conn = new Connetion();
    using(_cmd = new SqlCommand()){
        ------param------------
        using(SqlDataAdepter da = new SqlDataAdepter(_cmd)){
            da.Fill(dt)
        }
    }
    return dt;
}


public DataTable getCity(){
    DataTable dt = new DataTable();
    _conn = new Connetion();
    using(_cmd = new SqlCommand()){
        ------param------------
        using(SqlDataAdepter da = new SqlDataAdepter(_cmd)){
            da.Fill(dt)
        }
    }
    return dt;
}

//-------------

//Method

public void AllLists() {
    DataTable dt = new DataTable();
    country c = new country();
    dt = getCountry();
    country = (from DataRow dr in dt.Rows
        select new country(){
            countryid = dr["id"],
            states = ------how to add a states----,
            states.citys = ------------how to add citys-----
        });
}

ниже приведен формат, как я хочу получить данные
в формате json

страна: {
идентификатор : "",
имя : "",
Латы : "",
Долгое время : "",
состояния : {
идентификатор : "",
имя : "",
Латы : "",
Долгое время : "",
города : {
идентификатор : "",
имя ; "",
countryid : "",
stateid : ""
}
}
}

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