Plant Field ended in 2002.
Plant Field was created in 1899.
Plant
You cannot answer this without knowing the length of the field as well.
Because opposite charges attract. The negative end of the dipole moment is trying to get to the positive end of the field, and the positive end of the dipole is trying to get to the negative end of the field.
Meigs Field ended in 2003.
Forbes Field ended in 1971.
Weeks Field ended in 1951.
Breadon Field ended in 1960.
Marshall Field's ended in 2006.
Dugdale Field ended in 1932.
The Gathering Field ended in 2002.
Bettis Field ended in 1948.