Consuming a REST service

            string jsonRequest = "REST URL";
            CredentialCache credCache = new CredentialCache();
            credCache.Add(new Uri(jsonRequest), "NTLM", CredentialCache.DefaultNetworkCredentials);
            HttpWebRequest spRequest = (HttpWebRequest)HttpWebRequest.Create(jsonRequest);
            spRequest.Credentials = credCache;
            spRequest.UserAgent = "Mozilla/4.0+(compatible;+MSIE+5.01;+Windows+NT+5.0";
            spRequest.Method = "GET";
            spRequest.Accept = "application/json;odata=verbose";
            HttpWebResponse endpointResponse = (HttpWebResponse)spRequest.GetResponse();

            if (endpointResponse.StatusCode == HttpStatusCode.OK)
            {
                using (endpointResponse)
                {
                    using (var reader = new StreamReader(endpointResponse.GetResponseStream()))
                    {
                        JavaScriptSerializer serializer = new JavaScriptSerializer();
                        try
                        {
                            string jSON = reader.ReadToEnd();
                        }
                        catch (Exception ex)
                        {
                            throw ex;
                        }
                    }
                }
            }

Grouping datatable column using LINQ in C#

 Grouping datatable column using LINQ in C#

var grouped = from table in dt.AsEnumerable()

                          group table by new { placeCol = table["Place"] } into groupby

                          select new

                          {

                              Value = groupby.Key,

                              ColumnValues = groupby

                          };

            foreach (var key in grouped)

            {               

                Console.WriteLine(key.Value.placeCol);

                Console.WriteLine("---------------------------");

                foreach (var columnValue in key.ColumnValues)

                {

                    Console.WriteLine(columnValue["Name"].ToString());                   

                }

                Console.WriteLine();

            }

            Console.ReadLine();

For additional info:

http://www.c-sharpcorner.com/Blogs/10258/grouping-datatable-column-using-linq-in-C-Sharp.aspx