App.js

render() {
   return (
     <div>
           {this.state.posts.map((item, index) => (
           <div>
             <div class="row">
               <div class="leftcolumn">
                 <div class="card">
                   <div className= "title">
                     <h1>{item.title.rendered}</h1>
                   </div>
                   <div className= "content" dangerouslySetInnerHTML={{ __html: item.content.rendered }} />
                 </div>
               </div>
             </div>
           </div>
           ))}
     </div>
   )
 }