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:
Fort Revere
Table title:
Endicott period
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Name </th><th colspan=1 rowspan=1 > No. of guns </th><th colspan=1 rowspan=1 > Gun type </th><th colspan=1 rowspan=1 > Carriage type </th><th colspan=1 rowspan=1 > Years active </th></tr>
<tr> <td colspan=1 rowspan=1 > Ripley </td><td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > 12-inch gun M1888 </td><td colspan=1 rowspan=1 > barbette M1892 </td><td colspan=1 rowspan=1 > 1901-1943 </td></tr>
<tr> <td colspan=1 rowspan=1 > Sanders </td><td colspan=1 rowspan=1 > 3 </td><td colspan=1 rowspan=1 > 6-inch gun M1903 </td><td colspan=1 rowspan=1 > disappearing M1903 </td><td colspan=1 rowspan=1 > 1903-1943 </td></tr>
<tr> <td colspan=1 rowspan=1 > Pope </td><td colspan=1 rowspan=1 > 3 </td><td colspan=1 rowspan=1 > 6-inch gun M1903 </td><td colspan=1 rowspan=1 > disappearing M1903 </td><td colspan=1 rowspan=1 > 1903-1917 </td></tr>
<tr> <td colspan=1 rowspan=1 > Field </td><td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > 5-inch gun M1897 </td><td colspan=1 rowspan=1 > balanced pillar M1896 </td><td colspan=1 rowspan=1 > 1901-1917 </td></tr>
<tr> <td colspan=1 rowspan=1 > Antiaircraft Battery 1 </td><td colspan=1 rowspan=1 > 3 </td><td colspan=1 rowspan=1 > Unknown, possibly 3-inch gun M1917 </td><td colspan=1 rowspan=1 > Unknown, possibly AA pedestal </td><td colspan=1 rowspan=1 > 1936-1945 </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > AMTB 941 </td><td class="highlighted"  colspan=1 rowspan=1 > 4 </td><td class="highlighted"  colspan=1 rowspan=1 > 90 mm gun </td><td colspan=1 rowspan=1 > 2 fixed M3, 2 towed </td><td class="highlighted"  colspan=1 rowspan=1 > 1943-1946 </td></tr>
</table>
Question:
What was Fort Revere's latest addition to their artillery?
Answer:
A battery of four 90 mm guns known as AMTB 941 was built in Fort Revere in 1943.