A C# class holding constants for US Counties (a.k.a. parishes or boroughs) that are surfaced as an object called UsCountyDetails. This also references a listing of US States that reside in the Gist here: https://gist.github.com/Hallmanac/00946bfa7e028cee3a313f1c445ba216

UsCounties.cs

using System.Collections.Generic;
using System.Linq;

namespace Hallmanac
{
    public class UsCounties
    {
        public static UsCountyDetails FlAlachua { get; } = new UsCountyDetails("74227e90-7205-4c22-aab0-590bb06b7057", "Alachua", AllUsStates.Florida, 1);
        public static UsCountyDetails FlBaker { get; } = new UsCountyDetails("cb491b8d-481b-4970-a1d0-a92f1832511e", "Baker", AllUsStates.Florida, 2);
        public static UsCountyDetails FlBay { get; } = new UsCountyDetails("5b3be6cb-3f04-49c3-a94b-1f260c2688b0", "Bay", AllUsStates.Florida, 3);
        public static UsCountyDetails FlBradford  { get; } = new UsCountyDetails("5e04f90d-27e6-4c51-a2c1-5ac3b5cf12c6", "Bradford", AllUsStates.Florida, 4);
        public static UsCountyDetails FlBrevard  { get; } = new UsCountyDetails("0bcd7ea2-2a4c-4709-b9b2-2885f3e80550", "Brevard", AllUsStates.Florida, 5);
        public static UsCountyDetails FlBroward  { get; } = new UsCountyDetails("bb7bfd43-7bdc-4c8c-b9e4-8d77eac9ab88", "Broward", AllUsStates.Florida, 6);
        public static UsCountyDetails FlCalhoun  { get; } = new UsCountyDetails("17cb5ff7-d786-4059-b433-4abf8a728518", "Calhoun", AllUsStates.Florida, 7);
        public static UsCountyDetails FlCharlotte  { get; } = new UsCountyDetails("dca52378-3de9-485d-939d-1b23358b8c31", "Charlotte", AllUsStates.Florida, 8);
        public static UsCountyDetails FlCitrus  { get; } = new UsCountyDetails("5c0ddeac-000c-48cc-9ae7-2d153e6a847a", "Citrus", AllUsStates.Florida, 9);
        public static UsCountyDetails FlClay  { get; } = new UsCountyDetails("01ce1f1e-9359-473d-a69a-4e79ae6a6e21", "Clay", AllUsStates.Florida, 10);
        public static UsCountyDetails FlCollier  { get; } = new UsCountyDetails("b517650c-ee9f-44b6-9779-f30ff3ad7556", "Collier", AllUsStates.Florida, 11);
        public static UsCountyDetails FlColumbia  { get; } = new UsCountyDetails("9d0c6db8-b9b7-4924-846a-eb105e632a0a", "Columbia", AllUsStates.Florida, 12);
        public static UsCountyDetails FlDade  { get; } = new UsCountyDetails("7a2718c7-8437-4b0f-8ccf-efef3eadbf22", "Dade", AllUsStates.Florida, 13);
        public static UsCountyDetails FlDesoto  { get; } = new UsCountyDetails("6548b464-a780-4446-b8cc-6c269861c005", "Desoto", AllUsStates.Florida, 14);
        public static UsCountyDetails FlDixie  { get; } = new UsCountyDetails("1c3884e8-639c-4d2f-8a67-00344df4a512", "Dixie", AllUsStates.Florida, 15);
        public static UsCountyDetails FlDuval  { get; } = new UsCountyDetails("3f48da02-9ff5-4614-a254-3d2e1a77048c", "Duval", AllUsStates.Florida, 16);
        public static UsCountyDetails FlEscambia  { get; } = new UsCountyDetails("bacae5f6-cc0b-4bf1-9595-93f38669c926", "Escambia", AllUsStates.Florida, 17);
        public static UsCountyDetails FlFlagler  { get; } = new UsCountyDetails("a8437f30-b437-4f91-9d0d-eef752f2b85b", "Flagler", AllUsStates.Florida, 18);
        public static UsCountyDetails FlFranklin  { get; } = new UsCountyDetails("8928b2b1-5cd7-42b8-9917-489fc0ec9b93", "Franklin", AllUsStates.Florida, 19);
        public static UsCountyDetails FlGadsden  { get; } = new UsCountyDetails("d40b3068-89b5-41e0-8754-7c8198dcfdf6", "Gadsden", AllUsStates.Florida, 20);
        public static UsCountyDetails FlGilchrist  { get; } = new UsCountyDetails("11717d4a-8a36-4707-8a86-37f155f2324a", "Gilchrist", AllUsStates.Florida, 21);
        public static UsCountyDetails FlGlades  { get; } = new UsCountyDetails("07956abb-b711-4202-98e9-5ca81da20002", "Glades", AllUsStates.Florida, 22);
        public static UsCountyDetails FlGulf  { get; } = new UsCountyDetails("d61ff906-4058-4af7-aaba-ba55a937ab9d", "Gulf", AllUsStates.Florida, 23);
        public static UsCountyDetails FlHamilton  { get; } = new UsCountyDetails("e446277d-d5c2-4c61-835c-b4a3f5146436", "Hamilton", AllUsStates.Florida, 24);
        public static UsCountyDetails FlHardee  { get; } = new UsCountyDetails("04bd470b-e5b7-41d7-8a1f-60a311f3e503", "Hardee", AllUsStates.Florida, 25);
        public static UsCountyDetails FlHendry  { get; } = new UsCountyDetails("dfe55201-ccfb-41bb-a6fb-0a6b9d8e7ce0", "Hendry", AllUsStates.Florida, 26);
        public static UsCountyDetails FlHernando  { get; } = new UsCountyDetails("d44045b4-253e-4e21-8298-c1af243c0c3e", "Hernando", AllUsStates.Florida, 27);
        public static UsCountyDetails FlHighlands  { get; } = new UsCountyDetails("a614a8c3-d8d6-4dc3-a21b-d77271a64c09", "Highlands", AllUsStates.Florida, 28);
        public static UsCountyDetails FlHillsborough  { get; } = new UsCountyDetails("8517cbb9-d230-4a4d-9ced-40a3401f6b19", "Hillsborough", AllUsStates.Florida, 29);
        public static UsCountyDetails FlHolmes  { get; } = new UsCountyDetails("bde8029e-abb0-45b6-9a2f-4e683bcbf09e", "Holmes", AllUsStates.Florida, 30);
        public static UsCountyDetails FlIndian  { get; } = new UsCountyDetails("58890067-d1a7-4a7b-bae4-78cb05ea9b6b", "Indian", AllUsStates.Florida, 31);
        public static UsCountyDetails FlJackson  { get; } = new UsCountyDetails("02fe525b-ee85-4a76-bed6-364460221071", "Jackson", AllUsStates.Florida, 32);
        public static UsCountyDetails FlJefferson  { get; } = new UsCountyDetails("5746ce1c-f767-4944-9844-5d9a22dab343", "Jefferson", AllUsStates.Florida, 33);
        public static UsCountyDetails FlLafayette  { get; } = new UsCountyDetails("afff928b-4ef8-424e-816b-419a0bd5a005", "Lafayette", AllUsStates.Florida, 34);
        public static UsCountyDetails FlLake  { get; } = new UsCountyDetails("bf89b1ad-6704-4437-93c1-12d0f54e4261", "Lake", AllUsStates.Florida, 35);
        public static UsCountyDetails FlLee  { get; } = new UsCountyDetails("c363dc17-e1a2-44e2-b541-842f4411f3ac", "Lee", AllUsStates.Florida, 36);
        public static UsCountyDetails FlLeon  { get; } = new UsCountyDetails("bef879a8-dba2-4a58-a918-3a7eb6f77238", "Leon", AllUsStates.Florida, 37);
        public static UsCountyDetails FlLevy  { get; } = new UsCountyDetails("fd98a22c-b4fa-48b8-b1c8-600d5bfb9a09", "Levy", AllUsStates.Florida, 38);
        public static UsCountyDetails FlLiberty  { get; } = new UsCountyDetails("3dd0216f-2239-4fb9-b3c2-0c4c3da11eaf", "Liberty", AllUsStates.Florida, 39);
        public static UsCountyDetails FlMadison  { get; } = new UsCountyDetails("ee4bd433-9056-4d4f-96bd-566dacc64e89", "Madison", AllUsStates.Florida, 40);
        public static UsCountyDetails FlManatee  { get; } = new UsCountyDetails("7951b482-b086-41cb-930c-68cc47397fb1", "Manatee", AllUsStates.Florida, 41);
        public static UsCountyDetails FlMarion  { get; } = new UsCountyDetails("25c8e6c3-7035-4a64-8025-a8af48ecbb77", "Marion", AllUsStates.Florida, 42);
        public static UsCountyDetails FlMartin  { get; } = new UsCountyDetails("d5abd1e9-9d4e-4b76-90ba-0a00774a5414", "Martin", AllUsStates.Florida, 43);
        public static UsCountyDetails FlMonroe  { get; } = new UsCountyDetails("564ca9d0-ac23-491d-9d43-fd075085cdd7", "Monroe", AllUsStates.Florida, 44);
        public static UsCountyDetails FlNassau  { get; } = new UsCountyDetails("bebafcb4-d655-4447-8ef2-0adb80c44e2a", "Nassau", AllUsStates.Florida, 45);
        public static UsCountyDetails FlOkaloosa  { get; } = new UsCountyDetails("5feb0f09-64f3-4b50-b7cb-0d3c1a4e29d7", "Okaloosa", AllUsStates.Florida, 46);
        public static UsCountyDetails FlOkeechobee  { get; } = new UsCountyDetails("2e4c26a1-adbd-4e48-9301-bce4d769d65b", "Okeechobee", AllUsStates.Florida, 47);
        public static UsCountyDetails FlOrange  { get; } = new UsCountyDetails("72cd9516-2a86-4b1d-9e65-12a0ae98e521", "Orange", AllUsStates.Florida, 48);
        public static UsCountyDetails FlOsceola  { get; } = new UsCountyDetails("e0d9688b-550c-4624-8ae7-0064011f7e50", "Osceola", AllUsStates.Florida, 49);
        public static UsCountyDetails FlPalmBeach  { get; } = new UsCountyDetails("9a6970d7-f306-4376-b581-0e5392e43880", "Palm Beach", AllUsStates.Florida, 50);
        public static UsCountyDetails FlPasco  { get; } = new UsCountyDetails("a8f1f354-fabe-46ac-a8c4-78e8c4c688a5", "Pasco", AllUsStates.Florida, 51);
        public static UsCountyDetails FlPinellas  { get; } = new UsCountyDetails("7c9cc234-d9fd-4e38-bf16-c40edfece211", "Pinellas", AllUsStates.Florida, 52);
        public static UsCountyDetails FlPolk  { get; } = new UsCountyDetails("e7286f44-5574-4ff7-a3b5-a7ed65e94235", "Polk", AllUsStates.Florida, 53);
        public static UsCountyDetails FlPutnam  { get; } = new UsCountyDetails("ff4ba2f2-df3c-485b-a3fa-3df4ce4ec02f", "Putnam", AllUsStates.Florida, 54);
        public static UsCountyDetails FlSantaRosa  { get; } = new UsCountyDetails("5089661d-ec03-4100-8341-a69a8b86b632", "Santa Rosa", AllUsStates.Florida, 55);
        public static UsCountyDetails FlSarasota  { get; } = new UsCountyDetails("103bc2cc-2cec-47ca-8794-a633ed635266", "Sarasota", AllUsStates.Florida, 56);
        public static UsCountyDetails FlSeminole  { get; } = new UsCountyDetails("f38cefbe-70d3-435f-bfc4-6e225505d76b", "Seminole", AllUsStates.Florida, 57);
        public static UsCountyDetails FlStJohns  { get; } = new UsCountyDetails("395afc63-6eac-4096-b32b-24e64a73e5a2", "St Johns", AllUsStates.Florida, 58);
        public static UsCountyDetails FlStLucie  { get; } = new UsCountyDetails("93fc61bd-0452-4953-a004-461a8953eb8a", "St Lucie", AllUsStates.Florida, 59);
        public static UsCountyDetails FlSumter  { get; } = new UsCountyDetails("3abee0bc-731b-4f38-a846-588feb164fa9", "Sumter", AllUsStates.Florida, 60);
        public static UsCountyDetails FlSuwannee  { get; } = new UsCountyDetails("2d5e8fa6-86bb-4447-950e-473e7d123f40", "Suwannee", AllUsStates.Florida, 61);
        public static UsCountyDetails FlTaylor  { get; } = new UsCountyDetails("61a298c6-2a0d-4a36-95ed-368d2422023e", "Taylor", AllUsStates.Florida, 62);
        public static UsCountyDetails FlUnion  { get; } = new UsCountyDetails("124426dc-b7ca-4417-9d50-4f1f69a61029", "Union", AllUsStates.Florida, 63);
        public static UsCountyDetails FlVolusia  { get; } = new UsCountyDetails("b81c55dc-b589-42b6-b152-cef00a2bbb76", "Volusia", AllUsStates.Florida, 64);
        public static UsCountyDetails FlWakulla  { get; } = new UsCountyDetails("24e426fa-03fe-4229-b51b-c0ee2080dda5", "Wakulla", AllUsStates.Florida, 65);
        public static UsCountyDetails FlWalton  { get; } = new UsCountyDetails("c5371f6c-2262-4f85-adfa-2df7d2287a3d", "Walton", AllUsStates.Florida, 66);
        public static UsCountyDetails FlWashington  { get; } = new UsCountyDetails("8584db6f-8354-42f3-9580-8d5d7f996724", "Washington", AllUsStates.Florida, 67);
        
        public static List<UsCountyDetails> GetAllCounties()
        {
            var county = new UsCounties();
            var counties = typeof(UsCounties)
                .GetProperties()
                .Where(p => p.CanRead && p.GetGetMethod().IsPublic && (p.GetValue(county) as UsCountyDetails) != null)
                .Select(p => p.GetValue(county) as UsCountyDetails)
                .ToList();
            return counties;
        }
    }
}

UsCountyDetails.cs

namespace Hallmanac
{
    public class UsCountyDetails
    {
        public UsCountyDetails()
        {
            Id = Guid.NewGuid().ToString();
        }

        public UsCountyDetails(string id, string name, UsState state, int indexId = 0 )
        {
            Id = id;
            IndexId = indexId;
            CountyName = name;
            CountyState = state;
        }


        public UsCountyDetails(UsCountyDetails county)
        {
            Id = county.Id;
            IndexId = county.IndexId;
            CountyName = county.CountyName;
            CountyState = county.CountyState;
        }

        public int IndexId { get; set; }

        public string Id { get; set; }

        public string CountyName { get; set; }

        public UsState CountyState { get; set; }


        public string ToFullNameString() => $"{CountyName}, {CountyState}";


        public override string ToString() => $"{CountyName}";
    }
}