Fetching users from Express, while also using React Router

App.js

import React, { Component } from 'react';
import {
  BrowserRouter as Router,
  Route,
  Link
} from 'react-router-dom';
import './App.css';

class UsersView extends Component {
  state = {users: []}

  componentDidMount() {
    fetch('/users')
      .then(res => res.json())
      .then(users => this.setState({ users }));
  }

  render() {
    return (
      <div>
        <h1>Users</h1>
        {this.state.users.map(user =>
          <div key={user.id}>{user.username}</div>
        )}
      </div>
    );
  }
}

const Home = () => (
  <div>
    <h2>Home</h2>
  </div>
)


class App extends Component {
  render() {
    return (
      <div className="App">
        <Router>
          <div>
            <ul>
              <li><Link to="/">Home</Link></li>
              <li><Link to="/show-users">Users</Link></li>
            </ul>
            <Route exact path="/" component={Home}/>
            <Route path="/show-users" component={UsersView}/>
          </div>
        </Router>
      </div>
    );
  }
}

export default App;