Connect to Redshift VPC C #

Don't come off like a complete idiot here. I'm the .NET SQL Server guy trying to programmatically connect to AWS Redshift via C # for the first time, and I have an impossible time to get the connection. I honestly don't know much about AWS, so perhaps this is really obvious in relation to my problem. Here is my code:

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Data;
using Npgsql;

public class Redshift
{

    private readonly NpgsqlConnection _connection;

    private string _connectionString
    {
        get
        {
            NpgsqlConnectionStringBuilder builder = new NpgsqlConnectionStringBuilder();
            builder.Host = "xxx.xxxxxxxx.us-east-1.redshift.amazonaws.com";
            builder.Port = 5439;
            builder.UserName = "xxxx";
            builder.Password = "xxxx";

            return builder.ConnectionString;
        }
    }


    public Redshift()
    {
        _connection = new NpgsqlConnection(_connectionString);
        _connection.Open();
    }


}

Whenever I create Redshift, I get:

Failed to establish connection with 'xxx.xxxxxxx.us-east-1.redshift.amazonaws.com.

Setting the inbound rule for the VPC default security group to accept All Traffic 0.0.0.0/0 did not affect.