On 27 August Gálvez set out by land toward Baton Rouge, leading a force that consisted of 520 regulars, of whom about two-thirds were recent recruits, 60 militiamen, 80 free blacks and mulattoes, and ten Anglo-American volunteers headed by Oliver Pollock.[4] As they marched upriver, the force grew by another 600 men, including Indians and Acadians. At its peak, the force numbered over 1,400; this number was reduced due to the hardships of the march, by several hundred, before they reached Fort Bute.[5]