You can try this
C# 2.0 solution (no LINQ is required here).
using System;
using System.Collections.Generic;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
var list1 = new List<string> { "A", "B", "C" };
var list2 = new List<string> { "D", "E" };
var list3 = new List<string> { "F", "G", "H" };
var e4 = ConcatLists(list1, list2, list3);
var l4 = new List<string>(e4);
foreach (var item in l4)
Console.WriteLine(item);
Console.ReadKey();
}
public static IEnumerable<T> ConcatLists<T>(params List<T>[] lists)
{
foreach (var list in lists)
{
foreach (var item in list)
{
yield return item;
}
}
}
}
}