USMC Uniforms of the Pacific War

Olive drab fabrics are arguably just as iconic as denim in the world of heritage workwear. Whilst they were born out of problematic and harrowing circumstances, garments like OG107 pants and field jackets have become absolute staples in the world of heritage wear. If denim is the apple pie, olive HBT or sateen is cream, and combining the two leads to some of the sweetest and most reliable fits you can put together.

The OG107 uniform of the Vietnam War will probably always hold the crown in terms of overall popularity in the modern world, but anyone into heritage gear should be aware of the earlier USMC uniforms from WWII. Formulated in the Pacific War, the P41 and P44 uniform sets are HBT-laden military garb that also happens to be just as handsome as it is functional. They’re the forefathers of fatigues.

Pieces from the USMC uniforms from the Pacific War are referenced and reproduced by some of our favorite modern makers, including Buzz Rickson’s, The Real McCoy’s, and Warehouse. Today, we’ll be taking a closer look at the original USMC uniforms from the Pacific like P41 and P44, from their use of Frogskin camoflage and herringbone twill to the details of the iconic Monkey Pant, and beyond.

The Pacific War


Images from battle on Wake Island via Encyclopedia Britannica & Pinterest.

On 7th December 1941, Japanese military and naval forces launched breathtaking assaults on locations within the United States and British Empire, marking the dawn of the Pacific War. While tensions between the Allies and Japan had been brewing for a few years at this point, the U.S. was not prepared for the tactical prowess of the Japanese armed forces. The Allies suffered heavy defeats in key areas such as Guam, the Philippines, Singapore, and Wake Island, losing military bases and personnel along the way. Combat data from these skirmishes reported Japan’s cunning tactics, which included stealth, trickery, surprise assaults, and heavy concealment.


American reconnaissance patrol into the dense jungles of New Guinea, on December 18, 1942. Image via AP Photo/Ed Widdis

Up until 1941, the USMC didn’t have a specific field uniform. They had been using the Army’s ‘Enlisted Man’s Summer Service Uniform’ for warm weather operations. Some pieces from the aforementioned Enlisted Man’s Uniform did feature small edits for the USMC, but these really stopped at details like pocket shape and positioning, most likely included to enable differentiation between Army and USMC personnel.

As well as the aforementioned tactics used by the Japanese, the tropical climate of the Pacific also presented the Marines with new challenges. This new theater of war was harsh on uniforms, being hot, humid, full of venomous animals, and heavy with dense jungle that had already been mastered by the Japanese. Amphibious campaigns in the pacific required a strong fabric that could hold up to mosquitoes, high levels of moisture, a utilitarian design, and provide high comfort levels.

P41 — Utility Uniform


Reproduction P41 Uniform via SM Wholesale UK

The USMC issued the ‘Pattern Utility Uniform’ in the summer of 1942. A two-piece uniform made from 8.5 oz. olive HBT, the Utility Uniform was made up of the P41 pants and jacket, and was originally designed for mechanics and chore workers in the Army. Coming in a shade of olive often dubbed ‘sage’ or ‘seafoam green’, legend has it that Marines were fond of the way this fabric developed ‘salty’ patina as the dye chipped off the HBT through hard wear.

The P41 jacket is actually comparable to a chore coat, which makes sense seeing as that is essentially what is was having been adapted from a Utility Uniform. It had three patch pockets(one on the left chest, and two on the hips), a wide boxy fit, and embossed riveted metal buttons down the placket and on the adjustable cuffs. A custom USMC stencil was typically applied to the lone chest pocket. The matching trousers had a wide straight fit, matching metal button fly, and typically slash pockets at the front and patch pockets on the back. Metal donut buttons were used in most contracts for both pieces, often embossed with ‘U.S. MARINE CORPS.’.


An interesting image via Military Classic Memorabilia. Despite being taken in 1945, the Private pictured on the right wears the P41 Uniform.

Whilst developing new uniforms for jungle use, the Army and Marines noticed the qualities of the HBT Utility Work Uniform issued to mechanics. It was (and is) hardwearing, shrink and stretch-resistant due to its multi-directional weave, less prone to creasing and crinkling, all while being soft and supple with a handsome, comfortable drape.

Speaking of drape, the wide fit of the USMC Utility Uniform was possibly the biggest departure from other military uniforms worn by the USMC and Army. Both the winter and summer editions of the Army’s Enlisted Man’s Uniform were tailored with a more formal fit, but the new Utility garb was wide, boxy, and drapey, designed for ease of movement.


Modern styling of a vintage P41 Jacket via Brut Clothing

P42 — Camoflage Utility


Image via Uniforms of WWII.

Due to the covert elements of USMC campaigns, the Marines identified the need for a camoflage uniform early in the Pacific War. The push for camo was led by the legendary General MacArthur, who was concerned at how visible his troops were compared to the Japanese.

In response, the P42 uniform was issued in 1942. Based on the Utility Uniform, the P42 Uniform was made up of a coat and pants, and a matching helmet cover, all made up in a reversible HBT fabric that offered two different camoflages we now refer to as frogskin. This camoflage had already been deployed by the Army on both European and Pacific fronts in the form of a one-piece coverall suit, but the US Marine Corps stuck to the reliable silhouette of their Utility Uniform, with some updates.

Snap buttons were added to both garments of the P42 uniform to reduce snagging risk, and pocket placement was updated for ease of reversing the garments. For the Coat, the dual hip pockets were subbed for a singular button-closure patch pocket, and on the pants, the slash pockets of the Utility Uniform were replaced with large patch pockets (pocket bags needed for slash pockets would have gotten in the way). The snap button fly of the pants was also left exposed.


A reproduction P42 Uniform via SM Wholesale. Notice in addition to the inclusion of snap buttons, the adjustability of the cuffs on the jacket was also removed and replaced with a clean hem.


A reproduction P42 Uniform via SM Wholesale

P44 — Camo & Olive HBT


A reproduction P44 Camo Uniform via SM Wholesale.

Whilst the P42 uniform was widely issued, the pockets were a disaster. Marines complained about losing cigarettes and other rations, as well as equipment, due to the lack of fastening. In response, the USMC issued the P44 in the latter stages of the Pacific War. The uniform contained two new patterns, both of which were made of the same reversible ‘frogskin’ camo as the P42 gear.

The P44 Camo Coat was essentially a large, wide-fitting overshirt, shorter in length than the P41 jacket, but still with the button placket and adjustable cuffs. The biggest update, though, was the large chest cavities on either side of the button placket. They fasted with a handy snap button and were big enough to fit a box of K Rations in, amongst other bits. There isn’t any available knowledge as to why the USMC stencil was omitted, but with the war being in its later stages and with victory on the horizon, one can assume this omission was a cost-saving exercise for the final push.


Image via US Militaria Forum

The P44 Camo Pant also included large pocket cavities, which on most pairs, spanned around a large percentage of the top block. The pockets were accessible from just behind the outseam towards the hips, and fastened with 3-4 snap buttons, the number of which depended on the manufacturing contract. Many pairs were also issued with adjustable drawstring hems, but Marines often removed this string if they didn’t use it.

Depending on the contract, the pant’s fly and jacket placket would feature either tacked metal buttons or snaps.


Image via IMA.



A P44 HBT USMC Jacket from the last stages of the war, paired with some USMC Utility Pants, via Lot-Art

The above USMC uniform, also named P44 (or M44) is probably the most recognized among heritage heads, mainly because makers like Warehouse & Co., Buzz Rickson’s, and Bronson Mfg. have all made many reproductions of the coat.

The ironic thing is, this coat — and the ‘iconic’ P44 Monkey Pant, which I’ll get onto shortly — was only issued for a very short while at the end of WWII.  There are barely any images of this uniform being used in combat or in the field. You’d be lucky to find one online (I’ve tried). Due to its short issue time and lack of field exposure, it’s possible to pick up near-deadstock articles of this jacket.


An original P44 Jacket with an intact gas flap. Image via eBay.

The P44 HBT Coat is essentially the aforementioned P44 Camo Coat, made up of a newer shade of olive HBT, and with a USMC-stamped flap pocket on the chest. It still has the big pocket cavities on the chest, but it also had a gas flap, behind the button placket, added for extra protection against chemical weapons which were being used more and more towards the end of the Pacific War.


P-44 ‘Monkey’ Pants via The Major’s Tailor

We’ve all seen Monkey Pants in recent years. They had a bit of a moment in the early 2020s with some solid Japanese repros hitting the quality menswear market. They’re recognizable due to the ass pocket and wide pockets that span around the top block. There is some contention around the function of the ass pocket, but there is theory that it was for the standard issue poncho, which Marines would often tuck into their waistband. Again, these Pants really weren’t issued for very long, so there isn’t much field data to clarify how they were used in practice.


Images via IMA.

I’m pretty sure every contract for these P44 garments used stamped USMC-embossed Donut Buttons or Burst of Glory tack buttons.

Reality Check

Not Army: The unique weapons Marines got stuck with in the Pacific - Sandboxx

USMC Personnel in P42 Camo Uniform via Sanboxx

It’s important to note that, whilst HBT was issued to multiple personnel through most of WWII, including the USMC, tests actually showed it didn’t really perform that well in tropical climates. HBT was developed for workwear in the west, not navigating oppressive, humid jungles and islands. Assessments actually showed that HBT was too hot for the Pacific and that it became cumbersome when wet (which would have been a lot of the time). There were efforts to develop something better, but time, cost, and pressures of the war meant that a better alternative was never really found, and HBT was issued for the whole campaign. It’s facts like this that stand as further evidence of the pure bravery and heroism of those that fought in the Pacific.

Worthwhile Reproductions

P41 Utility Jacket


Bronson P41 Jacket, available for $80 from Olderbest.

P42 Pants


Available for $159 from SM Wholesale Ltd.

P44 Jacket


Available for $32 from American Classics.

Warehouse Monkey Pants


Available for $191 from Hinoya.



“U.S. Marines are seen as they advance against Japanese positions during the invasion at Tarawa atoll, Gilbert Islands, in this late November 1943 photo. Of the nearly 5,000 Japanese soldiers and workers on the island, only 146 were captured, the rest were killed.” – The Atlantic


The top block of an original and worn pair of USMC Utility Pants



Original P41 Jackets via Etsy


Original P42 Camo Jacket via Doyler on the U.S. Militaria Forum

Deadstock P41 via The Major’s Tailor


An original P44 Jacket via Fritz on the U.S. Militaria Forum


Original P44 Camo Coats via Flage Guy on the U.S. Militaria Forum


P44 button variations via Doyler on the U.S. Militaria Forum


P41 Utility Jacket and Pants (left and bottom) and P44 jacket via Lot-Art




Warehouse & Co. Monkey Pants, which are sold out at the time of writing. Image via Lost & Found.