React Router v4

app.jsx

// ...
import Routes from './routes';

const App = () => {
  return (
    <div className="container">
      <div className="starter-template">
        {/* ... */}
        <Routes />
      </div>
    </div>
  )
}

export default App;

main.jsx

// ...
import { BrowserRouter, HashRouter } from 'react-router-dom';

ReactDOM.render((
  <HashRouter>
    <App />
  </HashRouter>
), document.getElementById('app-root'));

routes.jsx

import React from 'react';
import { Switch, Route, Redirect } from 'react-router-dom';

import About from './components/About';
import Home from './components/Home';
import PageNotFound from './components/PageNotFound';
import ListTweets from './components/ListTweets';

const Routes = () => (
  <Switch>
    <Redirect exact from='/' to='/tweets'/>
    <Route exact path='/home' component={Home}/>
    <Route exact path='/about' component={About}/>
    <Route path='/tweets' component={ListTweets}/>
    <Route component={PageNotFound}/>
  </Switch>
)

export default Routes;