Ellen Johnson-Sirleaf, chosen president of Liberia last month in the country’s first free polling in its 183-year history, is the first woman elected to a presidency in Africa.

The choice of Ms. Johnson-Sirleaf is a remarkable breakthrough in a historically patriarchal society where women largely have been kept at the periphery in politics. She explicitly campaigned on her gender, and many of her supporters wore T-shirts that proclaimed, “All the men have failed Liberia; let’s try a woman this time.” It was a none-too-subtle reminder of the failure of men who have led the country into nearly two decades of authoritarian rule and civil strife from which it is only now emerging.