How do you implement accessibility in a React application?

Implementing accessibility in a React application involves several steps, including:

1. Using semantic HTML elements: Use the appropriate HTML elements to convey the meaning of the content on the page. For example, use <h1> for headings, <button> for buttons, and <label> for form elements.

2. Providing alternative text for images: Use the alt attribute to provide a text description of images for screen readers.

3. Managing focus: Ensure that the focus is moved to the appropriate element when a user interacts with the application, such as when a modal is opened or a new page is loaded.

4. Handling events: Use the onClick and onKeyDown events to handle user interactions in a way that is accessible to keyboard and screen reader users.

5. Using ARIA roles and attributes: Use ARIA (Accessible Rich Internet Applications) roles and attributes to provide additional information about the structure and purpose of elements on the page.

6. Testing: Test the application with assistive technology such as screen readers to ensure that it is accessible to users with disabilities.

7. Using libraries: There are libraries available such as react-a11y, react-aria, react-accessibility-hoc, etc, that can help you make sure your react application is accessible.

It's important to note that accessibility is an ongoing effort and should be incorporated into the development process throughout the entire lifecycle of the application.