Final answer:
John Brown's efforts were financially supported by a group known as the "Secret Six" who provided financial support to his raid on Harper's Ferry.
Step-by-step explanation:
John Brown's efforts were financially supported by a group known as the "Secret Six." These abolitionists, including Thomas Wentworth Higginson, Samuel Gridley Howe, Theodore Parker, Franklin Benjamin Sanborn, Gerrit Smith, and George Luther Stearns, provided financial support to Brown's raid on Harper's Ferry. They agreed to help him purchase weapons for his plan to attack the federal arsenal and incite slaves to rebel against their masters.