Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
List of ambassadors of the United States to Italy
Table title:
List of U.S. ambassadors to Italy
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Name and Title </th><th colspan=1 rowspan=1 > Presentation of Credentials </th><th colspan=1 rowspan=1 > Termination of Mission </th></tr>
<tr> <td colspan=1 rowspan=1 > George P. Marsh, Envoy </td><td colspan=1 rowspan=1 > 1871 </td><td colspan=1 rowspan=1 > July 23, 1882 </td></tr>
<tr> <td colspan=1 rowspan=1 > William Waldorf Astor, Envoy </td><td colspan=1 rowspan=1 > November 21, 1882 </td><td colspan=1 rowspan=1 > March 1, 1885 </td></tr>
<tr> <td colspan=1 rowspan=1 > John B. Stallo, Envoy </td><td colspan=1 rowspan=1 > November 27, 1885 </td><td colspan=1 rowspan=1 > June 6, 1889 </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > Albert G. Porter, Envoy </td><td class="highlighted"  colspan=1 rowspan=1 > June 6, 1889 </td><td colspan=1 rowspan=1 > July 9, 1892 </td></tr>
<tr> <td colspan=1 rowspan=1 > William Potter, Envoy </td><td colspan=1 rowspan=1 > December 28, 1892 </td><td colspan=1 rowspan=1 > March 8, 1894 </td></tr>
</table>
Question:
When was Albert G. Porter the US ambassador to Italy?
Answer:
Albert G. Porter was the US ambassador to Italy from 1889 to 1892.