The Paraíba Valley was the stage of military deployments by opposing forces during the 1964 Brazilian coup d'état: the rebel 2nd Army, coming from São Paulo towards Rio de Janeiro along the Via Dutra highway, and the loyalist School-Unit Group (; GUEs), coming from Rio de Janeiro in the opposite direction. The 2nd Army was commanded by General Amaury Kruel, in rebellion against the government of president João Goulart. The GUEs, led by Anfrísio da Rocha Lima, was subordinated to General Armando de Morais Âncora, from the 1st Army. Such movements were in progress or preparation in the early hours of 1 April, although the loyalist 2nd Army General Euryale de Jesus Zerbini delayed his army's movement. The Military Academy of Agulhas Negras (; AMAN), led by General Emílio Garrastazu Médici, and the 1st Armored Infantry Battalion (; 1º BIB), were halfway the road, respectively in the municipalities of Resende and Barra Mansa. Médici, forced to choose a side, joined the coup. The 1st BIB did the same.
In the morning, before the arrival of the 2nd Army and the GUEs, Médici occupied Resende and used his cadets to establish defensive positions along Via Dutra, towards Barra Mansa, from where he could resist the loyalists. The forces from São Paulo and Rio de Janeiro arrived around noon, with the former remaining further back, in Resende and Itatiaia, and the latter around Barra Mansa, with the academy's force in the middle, facing the loyalists. Combat, if it occurred, would begin between the cadets and GUEs soldiers. The loyalists were elite troops, with superior numbers and weaponry. The use of cadets on the front line also had a bad record in other countries. What Médici had in his favor was the effect of a "psychological brake" on the loyalist officers, who were unwilling to attack. Of the three artillery batteries sent against the academy, two immediately crossed the lines and defected to the rebels.
No confrontation occurred, as in the afternoon operations were interrupted by the arrival of generals Kruel and Âncora to negotiate within the academy. The defense mounted by Médici is considered important in forcing Âncora to negotiate, but it was part of a larger context of deterioration in the government's position. The resulting meeting "would once and for all mark the History of Brazil": the end of the 1st Army's resistance to the coup and the return of the troops to their barracks. Médici's reputation among the military grew, and his decision became part of the Army's collective memory.
The 1st BIB did not participate in the meeting of the military forces, as it was in Volta Redonda, where trade unionists, who opposed to the coup, unsuccessfully tried to paralyze the Companhia Siderúrgica Nacional, revealing themselves to be less organized than the military and industrial leaders.
Military background In a meeting with his generals around midnight on 31 March, Amaury Kruel sided his 2nd Army with the coup and ordered the invasion of Rio de Janeiro. At this time, the Tiradentes Detachment, a unit sent on campaign by general Olímpio Mourão Filho, had already crossed the border between Minas Gerais and Rio de Janeiro and come into contact with the loyalist forces sent from Guanabara and Petrópolis to confront it. By noon on 1 April, the detachment had advanced to the Areal region, facing the 2nd Infantry Regiment (; 2º RI). Meanwhile, the School-Unit Group (GUEs) would form the loyalist reaction to the 2nd Army.
Outside the Rio-São Paulo-Minas Gerais axis, São Paulo's western flank was Mato Grosso, whose 9th Military Region (; 9ª RM) was subordinate and loyal to the 2nd Army. The 16th Battalion of Caçadores, in Cuiabá, was ordered to advance to Brasília. The other flank was the southern region of Brazil, where the situation had not yet been decided until 2 April. The 5th Military Region, in Paraná and Santa Catarina, joined the coup, but not the entirety of the 3rd Army. Thus, on that day the 2nd Army sent reinforcements to the 5th Military Region, but the crisis ended before they were needed.
Beginning of the deployments
General Zerbini and loyalist reinforcements
The "military apparatus" of João Goulart's government, that is, the group of officers considered loyal and appointed to important positions, had as one of its most important figures in São Paulo the brigade general Euryale de Jesus Zerbini, commander of the Divisional Infantry of the 2nd Infantry Division (2nd DI). Zerbini did not attend the meeting of generals in São Paulo; having arrived in the city from 18:30 to 19:00, he was called by his superior and commander of the 2nd Infantry Division, Aluísio Miranda Mendes, before entering the HQ. Both sided with the government, with Aluísio promising to arrest Kruel if he rebelled. Zerbini was tasked with commanding the forces in the Paraíba Valley, a possible São Paulo–Rio invasion route through the Via Dutra highway. The local garrison consisted of the 5th and 6th Infantry Regiments (RIs) and the 2nd Combat Engineering Battalion (2nd BE Cmb). Zerbini was to be ready to move them.
At 21:00, Zerbini arrived at his headquarters in Caçapava, confirmed the loyalty of his subordinates and sent them in the direction of the rebels in Minas Gerais: the 5th RI of Lorena would take up positions in the direction of Itajubá, where the 4th BE Cmb from Minas Gerais was located, and in the Mantiqueira Tunnel, while the 6th RI from Caçapava would advance to the Paraíba do Sul river bridge in Jacareí and Campos do Jordão, on the way to Minas Gerais. Reconnaissance teams observed nothing unusual in these places and the regiments remained on standby in their barracks. But as the situation changed, at 22:30 Zerbini refused Aluísio's call to São Paulo. Contacted by general Assis Brasil and the president himself at 23:00 and 23:30, Zerbini said he was loyal and in control, but unable to resist an advance by the rest of the 2nd Army, and was then informed he'd be reinforced by tanks and general Anfrísio da Rocha Lima's GUEs.
The School-Unit Group's artillery component was the Artillery School-Group (GEsA). Each day a battery was on standby, and on the 31st it was 1st Lieutenant Hamilton Otero Sanches' 2nd Battery. According to his testimony, his group lived a moment of tension, and subordinates were uninformed and heard nothing from superiors. At night, a call to the group ordered an entire battery to follow the Infantry School-Regiment (REsI). He obeyed, but only to follow orders, as his political position was against "so much anarchy in our country". At the suggestion of one of his staff officers, Captain Sílvio Pereira Brunner, he first consulted his commander. That was loyalist Colonel Aldo Pereira, who was sleeping. Once awake, he simply said "Yes, they called you, you will go", without showing the slightest interest in what one of his own batteries would do, negatively impressing Sanches. To save time, he presented himself without his troops to the REsI's commander, Colonel Abner Moreira. In what Sanches' saw as an absurd moment, Abner gave orders to his sub-unit even though it belonged to another formation whose commander was in the same barracks. He was sent to the Rio–São Paulo axis, leaving after midnight, and on the way he met the REsI battalion, which had already left, under Major Simon. They talked found themselves with a similar political position.
The 3rd Battery belonged to Captain Affonso de Alencastro Graça. He was, in contrast to the loyalists, "among those who thought something had to be done". Their operations staff officer, Captain Willy Seixas, and the battery commanders found that it would be impossible to rise up inside the barracks, as they would be surrounded. Instead, they agreed to move forward and, wherever they went, they would join the "revolutionary forces". The 3rd Battery and the 1st, of Captain José Antônio da Silveira, followed behind the vanguard.
The GUEs also had the 1st Group of 90mm anti-aircraft guns, from which the 2nd battery was moved, under Captain Brilhante Ustra. Ustra recounted an unusual arrangement: the soldiers, corporals and captain were actually from the 4th battery, and an older captain, Cavalero, accompanied him in the command jeep. Ustra had realized that the objective of the arrangement was for the most politically reliable elements, Cavalero and the sergeants, to take control, and after protests he managed to get the soldiers and corporal to be his own. In addition to the division between supporters and opponents of the government within the battery itself, it would leave without nurses and kitchen supplies and with very little food and water. A movement over asphalt would wear out the rubber tracks on the tractors that towed the guns, and the battery would be useless in providing anti-aircraft support to a moving column, as its function was to defend sensitive points and it took hours to get into position. This battery was to depart in the morning.
Movement of the 2nd Army
Zerbini managed to retain his troops in their quarters on the night of 31 March, but in the early hours of 1 April his authority dissolved. At 01:00 he tried to contact the 5th RI, only to discover that the barracks were empty and the men had left in trucks. He sent a motorized patrol in search of the regiment, but it never gave him any news. At 06:00 he heard from the commander of the 6th RI that he would advance to Resende under direct orders from Kruel. Between 6 and 7 o'clock, he communicated with Aluísio, who declared himself on the rebel side and moved through the valley with the 2nd Mechanized Reconnaissance Squadron. For Zerbini, the only thing left to do was delay the 2nd Army until the arrival of troops from Rio de Janeiro. He managed to accompany Aluísio to Resende, from where he intended to leave for Rio de Janeiro, but ended up being arrested at AMAN.
The 5th RI managed to travel in army trucks and three private buses, and the 6th, in private trucks and the Pássaro Marrom company's buses. The 1st Light Tank Battalion (BCCL) from Campinas continued to board trains, although, according to Colonel Cid de Camargo Osório, from the General Staff of the 2nd Army, its movement was delayed by the "internal enemy", which managed to cut off electricity supply. The transport situation was difficult, and they had to provide resources to personnel who were still on foot. Fuel along the way was guaranteed by governor Adhemar de Barros. Under his order, Postos Atlantic's petrol stations filled vehicle tanks "without bureaucracy; a 'note' was signed and that was it".