Question: Who constructed buildings in Rome that stood against the forces of Mark Anthony and Cleopatra in 31 BC, Marcus Vipsanius Agrippa or Vipsania Polla?

Context paragraphs:
Herod Agrippa: Herod Agrippa, also known as Herod or Agrippa I (Hebrew: אגריפס‎ ) (11 BC – 44 AD), was a King of Judea from 41 to 44 AD.  He was the last ruler with the royal title reigning over Judea and the father of Herod Agrippa II, the last King from the Herodian dynasty.  The grandson of Herod the Great and son of Aristobulus IV and Berenice, he was born Marcus Julius Agrippa, so named in honour of Roman statesman Marcus Vipsanius Agrippa.  He is the king named Herod in the Acts of the Apostles 12:1: "Herod (Agrippa)" (Ἡρώδης Ἀγρίππας ).  Josephus states that he was known in his time as "Agrippa the Great".

Pons Agrippae: The Pons Agrippae (Bridge of Agrippa) was an ancient bridge across the River Tiber in Rome.  It was located 160 metres above the Ponte Sisto, and is known from an inscribed cippus set up by the curatores riparum during the Principate of the Emperor Claudius, suggesting it was built during or before the reign of Claudius.  It was restored in 147 AD.  The bridge is named after Marcus Vipsanius Agrippa, a close friend of the Emperor Augustus.  Agrippa married Julia, the daughter of Augustus, and the couple lived in a villa on the opposite bank of the River Tiber.  To connect his villa to the Field of Mars, where Agrippa had built several important monuments, it has been suggested that Agrippa constructed the Pons Agrippae.

Gaius Caesar: Gaius Caesar (20BC – 21 February 4AD), formally Gaius Julius Caesar (Latin: "Caius Caesar Augustus filius"), was the adopted son and heir of Augustus.  He was born the son of Augustus' trusted friend and general, Marcus Vipsanius Agrippa.  His name at birth was Gaius Vipsanius Agrippa, but it later changed to Gaius Julius Caesar, following his adoption out of the "Vipsanii" and into the "Julii" by Augustus.  He along with his brother Lucius, born in 17BC, were intended to rule the Roman Empire together.

Marcus Vipsanius Agrippa: Marcus Vipsanius Agrippa ( ; 64/62 BC – 12 BC) was a Roman consul, statesman, general and architect.  He was a close friend, son-in-law, and lieutenant to Octavian and was responsible for the construction of some of the most notable buildings in the history of Rome and for important military victories, most notably at the Battle of Actium in 31 BC against the forces of Mark Antony and Cleopatra.  As a result of these victories Octavian became the first Roman Emperor, adopting the name of Augustus.  Agrippa assisted Augustus in making Rome a city of marble and renovating aqueducts to give all Romans, from every social class, access to the highest quality public services.  He was responsible for the creation of many baths, porticoes and gardens, as well as the original Pantheon.  Agrippa was also father-in-law to the second Emperor Tiberius, maternal grandfather to Caligula, and maternal great-grandfather to the Emperor Nero.

Battle of Actium: The Battle of Actium was the decisive confrontation of the Final War of the Roman Republic, a naval engagement between Octavian and the combined forces of Mark Antony and Cleopatra on 2 September 31 BC, on the Ionian Sea near the promontory of Actium, in the Roman province of Epirus Vetus in Greece.  Octavian's fleet was commanded by Marcus Vipsanius Agrippa, while Antony's fleet was supported by the power of Queen Cleopatra of Ptolemaic Egypt.

Agrippa Postumus: Agrippa Postumus (26 June 12 BC – 20 August AD 14), also referred to as Postumus Agrippa, was a son of Marcus Vipsanius Agrippa and Julia the Elder.  He was originally named Marcus Vipsanius Agrippa Postumus in honor of his father, who died shortly before Postumus' birth.  After the deaths of his older brothers, Lucius (d. AD 2) and Gaius Caesar (d. AD 4), Postumus was adopted by his maternal grandfather, the Roman emperor Augustus.  In accordance with Roman naming conventions, Postumus' name was changed to Marcus Julius Caesar Agrippa Postumus.  At the time Augustus considered Postumus as a potential successor, but banished him from Rome in 9AD, for reasons that remain unknown.  This, in effect, though not in law, cancelled his adoption and virtually assured Tiberius' position as Augustus' sole heir.  Postumus was ultimately executed by his own guards shortly after Augustus' death in AD 14.

Vipsania Polla: Vipsania Polla was the daughter of Lucius Vipsanius Agrippa (a man of equestrian rank) and sister to another Lucius Vipsanius Agrippa, as well as the Roman general and politician Marcus Vipsanius Agrippa.  Polla lived during the late Roman Republic and during the reign of Rome's first Emperor Augustus.

Lucius Vipsanius Agrippa: Lucius Vipsanius Agrippa was the father of the Roman politician and general Marcus Vipsanius Agrippa, the distinguished Roman woman Vipsania Polla, and another Lucius Vipsanius Agrippa.

Campus Agrippae: The Campus Agrippae is the area within the boundaries of ancient Rome named after Marcus Vipsanius Agrippa.  A number of construction projects were developed within its perimeters, including the "Porticus Vipsania", built by his sister, Vipsania Polla, and finished by Augustus, which ran along the western perimeter, against the Via Lata.  There was also a race course.  In 7 BCE, Augustus declared the Campus open to the public.

Vipsania Marcella: Vipsania Marcella Agrippina or Marcellina or Vipsania Tertia (born 27 BC or later) was perhaps the only daughter of Roman statesman Marcus Vipsanius Agrippa by his second wife Claudia Marcella Major.  If so, she was the first grandchild to Octavia Minor and first great-niece to Roman Emperor Augustus.  If she truly had the name Marcella, there is no way that she was a daughter of Agrippa's first wife, Caecilia Attica.  She and her elder sisters Vipsania Agrippina were married off to Q. Haterius (cos. 5 BC), Publius Quinctilius Varus (cos. 13 BC) and Tiberius (also cos. 13 BC) respectively.  Nepos "Att".  19 records the birth of Tiberius's future wife before the death of Atticus.  She and Haterius had a son, Q. Haterius Agrippa, who was consul in AD 22 at a youthful age (probably the legal minimum 33 with a ten-year dispensation as a grandson of Agrippa).

Supporting paragraphs: Vipsania Polla Marcus Vipsanius Agrippa
Answer: most notably at the Battle of Actium in 31 BC against the forces of Mark Antony and Cleopatra.