The navy fared better in the years 1900 to 1914, with an active shipbuilding program which gave the United States the third largest navy in the world. The army and navy returned to traditional duties with their organizations virtually unchanged, although Congress added two infantry and two cavalry regiments of African Americans to the army. The American squadron slipped into the bay after midnight on May 1 and began its attack at dawn. Despite poor marksmanship, the stronger American fleet destroyed all five Spanish gunboats and several other ships. The American public, ironically, reacted with horror when it learned of Waller's actions in carrying out Smith's order. US-Mexican relations were already uneasy when on April 9,1914, Mexican authorities mistakenly arrested eight American sailors from the USS Dolphin in Tampico. President Woodrow Wilson, having already decided to intervene in the Mexican civil war, demanded a public apology from Mexican president Victoriano Huerta.