GNU g++ separate file compilation error - undefined reference

I am a newbie to C/C++ programming. Previously I have worked in Java, cobol, etc.

I have a program (List.h/List.cpp) that I intend to use later as a library program. I have compiled and tested this program with the "main" function inside the List.cpp file, it compiles and runs ok. The problem is that when I separate the "main" function and put it in a new file called main.cpp, I start getting "undefined reference" compilation errors.

I have tried using "friend" and "extern" in a main.h file but I am unable to get it working with it. Any insight into what I am doing wrong is more than welcome. I have edited out the unnecessary code.

Compilation Errors

username@username-virtual-machine:~/Source/CppMine$ make
g++ -Wall -std=c++11 -c -g List.cpp -o List.o
g++ -Wall -std=c++11 -c -g main.cpp -o main.o
g++ -Wall -std=c++11 -g  List.o  main.o   -o main
main.o: In function `main':
/home/username/Source/CppMine/main.cpp:19: undefined reference to `List<int>::List()'
.....

File "List.h"

#ifndef H_List
#define H_List  

//Definition of the node
template <class Type>
struct nodeType
{
    Type info;
    nodeType<Type> *next;
};

template <class Type>
class List
{
public:
    List();

    ~List();

    int count;
    nodeType<Type>* first;
};

#endif

File "List.cpp"

#include <iostream>
#include "List.h"

using namespace std;

template <class Type>
List<Type>::List()  //default constructor
{
    count=0;
    first=NULL; 
}

template <class Type>
List<Type>::~List( void )
{
    nodeType<Type>* current=first;
    first=NULL;
    nodeType<Type>* link=NULL;
    while ((count>0) & (current!=NULL))
    {
        link = current->next;
        delete current;
        current=link;
        link=NULL;
        count--;
    }
}

File "main.cpp"

#include <iostream>
#include "List.h"

using namespace std;

int main(int argc, char** argv) {
    cout << "\t\tC++ Data Structures" << endl;
    cout << "\t\t===================" << endl << endl;
    cout << "** About to test NodeLinked for Integers..." << endl;
    List<int>* myint0 = new List<int>;
    delete myint0;   
    cout << "** About to test NodeLinked for Chars...." << endl;    
    List<char>* mychars = new List<char>;
    delete mychars;
}