Historical map illustrating the territorial expansion of the United States between 1800 and 1850, including major events and the impact of westward movement.

Let’s solve this step by step.

We are given a table with three columns:
- “Antes de 1800” (Before 1800)
- “Para la década de 1850” (By the 1850s)
- “Impacto en la expansión” (Impact on expansion)

And we have four rows of transportation methods to fill in:

1. Barcos movidos por remos/velas → ? → ?
2. Carretas tiradas por caballos → ? → ?
3. Pequeñas imprentas → ? → ?

Wait — actually, looking again, the third row says “Pequeñas imprentas” but that doesn’t fit with transportation. Let me check the original image description.

Actually, from the context and typical U.S. history curriculum, this is about how transportation changed before 1800 vs. by the 1850s, and how each change helped expand the country.

The correct categories should be:

Row 1: Water transport
Row 2: Land transport (wagons)
Row 3: Communication? Wait — no, “imprentas” means printing presses — that’s not transportation. That might be a mistake or mislabeling.

But looking at the map timeline in the image (even though we can’t describe it), it shows events like:

- 1803: Louisiana Purchase
- 1811: First steamboat on Mississippi
- 1825: Erie Canal opens
- 1830s: Railroads begin
- 1840s: Telegraph invented
- 1849: Gold Rush

So likely, the table is meant to compare old vs. new technologies and their impact on westward expansion.

Let’s reinterpret the rows based on standard U.S. history content:

Probably the intended rows are:

1. Boats (water transport)
2. Wagons (land transport)
3. Communication (like telegraph or newspapers) — even though “imprentas” = printing presses, which spread news.

But let’s stick to what’s written and match logically.

Given:

Before 1800:
- Barcos movidos por remos/velas → Rowboats/sailboats
- Carretas tiradas por caballos → Horse-drawn wagons
- Pequeñas imprentas → Small printing presses

By the 1850s:
We need to write what replaced or improved these.

For boats: Steamboats became common after 1807 (Fulton’s Clermont). By 1850s, steamboats dominated rivers.

For wagons: Still used, but now also railroads started appearing. However, for overland travel to West, covered wagons still used until railroads reached further. But by 1850s, railroads were expanding fast.

For printing presses: Before 1800, small local presses. By 1850s, larger presses, faster printing, more newspapers — especially with telegraph helping distribute news quickly.

Now, “Impacto en la expansión”:

- Steamboats allowed moving goods/people upriver easily → helped settle Midwest.
- Railroads moved people/goods faster across land → opened up Great Plains.
- Printing presses + telegraph → spread information about land opportunities, gold rush, etc. → encouraged migration.

So let’s fill the table accurately:

---

Row 1: Barcos movidos por remos/velas

→ Antes de 1800: Remos/velas (row/sail)

→ Para la década de 1850: Barcos de vapor (steamboats)

→ Impacto en la expansión: Permitieron navegar contra la corriente y transportar mercancías y personas más rápido por los ríos, facilitando el asentamiento del Medio Oeste.

---

Row 2: Carretas tiradas por caballos

→ Antes de 1800: Carretas lentas, solo para corta distancia

→ Para la década de 1850: Ferrocarriles (railroads) — although wagons still used, railroads were the big innovation

→ Impacto en la expansión: Conectaron este y oeste, permitiendo mover grandes cantidades de personas y bienes rápidamente, acelerando la colonización del Oeste.

*(Note: Some might say “carretas cubiertas” for 1850s, but railroads had bigger impact. Since the column says “para la década de 1850”, and railroads began in 1830s and expanded rapidly by 1850s, it’s appropriate.)*

---

Row 3: Pequeñas imprentas

→ Antes de 1800: Imprentas pequeñas, producción lenta, poca distribución

→ Para la década de 1850: Imprentas grandes y telégrafo — but since the row is “imprentas”, maybe just “impresión masiva” or “periódicos nacionales”

Actually, better: Periódicos impresos en masa y distribuidos ampliamente

→ Impacto en la expansión: Difundieron noticias sobre tierras disponibles, fiebre del oro, y oportunidades en el Oeste, motivando a miles a migrar.

---

But wait — the table has only three rows, and the third one is “Pequeñas imprentas”. In many textbooks, they include communication as part of expansion tools.

Alternatively, perhaps the third row was meant to be “Mensajes entregados a mano” or something, but it says “imprentas”.

Looking back at user’s text:

“Cartas movidas por remos/velas” — wait, no, first row is “Barcos movidos por remos/velas”

Second: “Carretas tiradas por caballos”

Third: “Pequeñas imprentas”

Fourth: ??? There’s a fourth row mentioned in the initial problem? No, in the user input, it shows three rows under the table.

Wait, in the original message, it says:

```
Barcos movidos por remos/velas Mensajes entregados a mano
Carretas tiradas por caballos Ferrocarriles
Pequeñas imprentas Imprentas a gran escala
```

Oh! I see — in the “Para la década de 1850” column, some answers are already filled!

Look:

In the user’s text:

Under “Para la década de 1850”:

- First row: “Mensajes entregados a mano” — that doesn’t make sense for boats. Probably a typo or misalignment.

Wait, let’s read carefully:

User wrote:

```
Barcos movidos por remos/velas Mensajes entregados a mano
Carretas tiradas por caballos Ferrocarriles
Pequeñas imprentas Imprentas a gran escala
```

This seems like the “Para la década de 1850” column already has entries, but they don’t match the left column.

That must be a formatting error.

Actually, re-examining:

The table structure is:

| Antes de 1800 | Para la década de 1850 | Impacto en la expansión |
|------------------------|------------------------------|--------------------------|
| Barcos... | [blank?] | [blank] |
| Carretas... | Ferrocarriles | [blank] |
| Pequeñas imprentas | Imprentas a gran escala | [blank] |

And the first row under “Para la década de 1850” says “Mensajes entregados a mano” — but that would be for communication, not boats.

I think there’s a mix-up.

Perhaps the first row is supposed to be about communication? But it says “Barcos”.

Another possibility: Maybe “Mensajes entregados a mano” is a distractor or misplaced.

Let me look at the actual image description provided earlier — but we can't describe images.

Based on standard knowledge and logic:

Correct matching:

1. Transportation by water:
- Before 1800: Sail/row boats
- By 1850s: Steamboats
- Impact: Enabled upstream travel, boosted trade and settlement along rivers

2. Transportation by land:
- Before 1800: Horse-drawn wagons
- By 1850s: Railroads (and still wagons, but railroads key)
- Impact: Faster movement across continent, linked regions

3. Communication:
- Before 1800: Small printing presses, hand-delivered messages
- By 1850s: Mass printing, telegraph
- Impact: Spread information quickly, encouraged migration

But in the table, the third row is “Pequeñas imprentas”, and “Para la década de 1850” is “Imprentas a gran escala”, which makes sense.

Then what is “Mensajes entregados a mano”? It might be for a different row, but there are only three rows shown.

Perhaps the first row's "Para la década de 1850" is blank, and "Mensajes entregados a mano" is a mistake.

To resolve this, I'll assume the table is:

Row 1: Water transport
- Antes de 1800: Barcos movidos por remos/velas
- Para la década de 1850: Barcos de vapor
- Impacto: Permitieron viajar contra la corriente y transportar carga pesada, facilitando el comercio y asentamiento en el interior.

Row 2: Land transport
- Antes de 1800: Carretas tiradas por caballos
- Para la década de 1850: Ferrocarriles
- Impacto: Redujeron el tiempo de viaje de meses a días, conectando costas y promoviendo la migración al Oeste.

Row 3: Communication
- Antes de 1800: Pequeñas imprentas (y mensajes entregados a mano — perhaps combined)
- Para la década de 1850: Imprentas a gran escala (y telégrafo, but not listed)
- Impacto: Difundieron noticias sobre oportunidades en el Oeste, como la fiebre del oro, atrayendo settlers.

But in the user's text, for row 1, "Para la década de 1850" is written as "Mensajes entregados a mano", which is likely an error. Probably, it should be "Barcos de vapor".

Similarly, "Mensajes entregados a mano" might belong to communication, but it's placed under boats.

To fix this, I'll provide the correct historical answers.

Final decision:

Fill the table as follows:

Row 1: Barcos movidos por remos/velas
- Para la década de 1850: Barcos de vapor
- Impacto en la expansión: Podían navegar contra la corriente de los ríos, lo que permitió llevar suministros y personas al interior del continente, impulsando el asentamiento del Medio Oeste.

Row 2: Carretas tiradas por caballos
- Para la década de 1850: Ferrocarriles (as given in user's text)
- Impacto en la expansión: Viajaban mucho más rápido que las carretas, uniendo el este con el oeste y haciendo posible la migración masiva hacia las nuevas tierras.

Row 3: Pequeñas imprentas
- Para la década de 1850: Imprentas a gran escala (as given)
- Impacto en la expansión: Produjeron periódicos y folletos en masa que informaban sobre tierras baratas y oportunidades en el Oeste, animando a muchas familias a mudarse.

Note: "Mensajes entregados a mano" is probably a misplacement; it should be under communication before 1800, but since the row is "Pequeñas imprentas", we'll go with that.

So, completing the table:

| Antes de 1800 | Para la década de 1850 | Impacto en la expansión |
|------------------------|------------------------------|--------------------------|
| Barcos movidos por remos/velas | Barcos de vapor | Podían navegar contra la corriente, facilitando el transporte y asentamiento en el interior. |
| Carretas tiradas por caballos | Ferrocarriles | Viajes más rápidos y seguros, conectando regiones y promoviendo la migración al Oeste. |
| Pequeñas imprentas | Imprentas a gran escala | Difundieron información sobre oportunidades en el Oeste, incentivando la expansión poblacional. |

This matches historical facts and fills the blanks logically.

Final Answer:

Barcos de vapor
Podían navegar contra la corriente, facilitando el transporte y asentamiento en el interior.

Ferrocarriles
Viajes más rápidos y seguros, conectando regiones y promoviendo la migración al Oeste.

Imprentas a gran escala
Difundieron información sobre oportunidades en el Oeste, incentivando la expansión poblacional.